21 Back-Stabbing Cheaters Who Had An Affair With Their Partners' Friends Or Family Members

We asked members of the BuzzFeed Community if they've ever been with someone who cheated on them with one of their friends or family members. Apparently, this atrocious act is more common than you'd think! Here's what people shared:

1."My husband cheated on me with my best friend of almost 10 years. Our old housemate had moved out, which left our extra bedroom open. My BFF moved in. A couple months later, she up and disappears for days. Then, she started acting super weird and kept avoiding me. Come to find out via a friend that my husband had sex with her while I was at work. It gets better, though! They did it in our bed. But wait, IT GETS EVEN BETTER. He did it to get revenge on me for cheating on him years prior. He admitted later that he did it intentionally to get back at me."

"I had cheated years prior and regret it to this day because of the pain it caused. He also effectively destroyed my closest friendship with his 'payback.' I lost my friend group by extension. We did stay together, but against my better judgment. If anyone cheats on you and is even a fraction of this cold and calculating, just head for the hills y'all...please."

samisunshine23

2."This is my friend's story. So, her ex-boyfriend cheated on her with her stepmom. Her mom wasn't really in her life because she and daddy dearest had gotten divorced. So, when her dad met her stepmom (we'll call her Vivica), we were in our teens and juniors in high school. My friend was over the moon to finally have a mom figure in her life. Vivica and my friend did everything together; they were extremely close. One day, my friend calls me in tears, and it's for the sickest reason. Her boyfriend at the time had broken up with her because he had been cheating with Vivica. And, since he was 18, he wanted to date Vivica instead of my friend because Vivica was a 'better woman.' Eventually her dad found out, and he and Vivica got divorced. Luckily, my friend is doing much better and has blocked most of her family, and is currently studying to become a ICU nurse!"

queenlovie

  Motortion / Getty Images/iStockphoto
Motortion / Getty Images/iStockphoto

3."My father. His brother (my uncle) was in the hospital for a couple of months dying of cancer when suddenly my father started staying the night at his sister-in-law’s (my dying uncle’s wife) place to 'comfort her.' We all knew what they were doing, and my uncle even accused the two of them of cheating while on his death bed. A week after we buried my uncle, my father left my mother for his sister-in-law. Apparently, my father married his sister-in-law a few years after the divorce went through. I have zero contact with my father after everything he put us through."

—Anonymous

4."I cheated on my husband with my stepsister's husband (my brother-in-law). My mom was married to my stepsister's dad. We had an affair for about six months, and I eventually got caught by my husband and he exposed us to all of our family and friends on social media before I could tell anyone. My marriage was over, but at the time, I wasn't sad. I continued to see the other person for a little bit after the fact, but eventually that stopped. His marriage was on the rocks and it affected my mom's marriage as well since she was married to my stepsister's dad."

—Anonymous

  Aitor Diago / Getty Images
Aitor Diago / Getty Images

5."He was my first boyfriend in high school. I was young, naïve, and completely in love with him. He was my first everything. After six months, I found out he was sleeping with my best friend. Losing the two most important people in your life at the same time sucks, but I’m definitely much better without either of them around."

—Anonymous

6."My ex-husband cheated with my best friend, who was a bridesmaid in our wedding. They had a kid before I could even file for divorce. She and I had been somewhat estranged around this time due to her erratic behavior and the lies I kept catching her in. In hindsight, it was probably taking a lot of mental energy to conceal the affair and keep her stories straight, but it never occurred to me at the time. She was with the father of her children too, and had recently had another baby with him, so two families were ruined in this process. All for them to stay together only two years, have another baby, and become the most toxic versions of themselves possible."

"Now my daughter hasn’t seen her father at all in years and has a half-sister she has no relationship with (not for lack of trying on my part). I was absolutely devastated at first, particularly with the baby announcement because I am unable to have more kids. It was a slap in the face. Since then, I’ve realized it was for the best and I’ve been able to get to a really good place in life while they are doing horribly. My ex ended up having another kid with his family member's ex, so clearly he likes to keep things close to home!"

kaylamoyer4

  Hans Neleman / Getty Images
Hans Neleman / Getty Images

7."My boyfriend of four years, with whom I owned a home, cheated on me with a mutual friend of ours from work. How did I find out? We bought a Sleep Number bed when we bought the house, and while I was out of state for a wedding, I saw that two people were in the bed...and they weren’t doing a lot of sleeping."

—Anonymous

8."When I started dating my ex, he was new in town and was looking for friends, so I introduced him to a couple of mine and he hit it off with them. We would all hang out together, and while usually it was great fun, there were several times where my ex would be blatantly flirting with one of my close friends (let’s call her Sam). I would always ask my ex not to flirt with Sam, but he would tell me I was imagining things and that he was just being friendly. Cut to a year or so later, and my ex dumped me out of the blue. I was heartbroken and cried on Sam’s shoulder about how much I still loved him, and she would always reassure me that if it was meant to be, we would reconcile."

"Well, only a few weeks later, our mutual friend messaged me to say he found out that Sam and my ex had been sleeping together the entire time. I had never felt so betrayed and broken, and it took a long time to get over what they had done. But, I also felt vindicated knowing I hadn’t been imagining things, and that my ex HAD been flirting with her right in front of me."

liz_adams

  Prostock-studio / Getty Images/iStockphoto
Prostock-studio / Getty Images/iStockphoto

9."My then-boyfriend (now ex), who I had been seeing for about three years, cheated on me with my sister. Luckily, it didn't go on for very long (like less than a month) before I caught them. They had been exchanging flirty texts and seeing each other behind my back. Unsurprisingly, I never got an apology from either one of them. Apparently neither of them thought they did anything wrong. My sister had the nerve to cry and be offended when I cut her out of my life. I had to block her on my phone because she kept bombing me with messages saying, 'I have a bad feeling about this.' 🙄 I also considered a restraining order because she kept coming to my door."

"Sadly, some relatives took her side, because 'she has been going through some issues.' She has always painted herself as the victim in everything and has never taken responsibility for her actions, so I can't imagine the version she gave to the relatives. This also was not the first time she did something like this. She has a history of trying to date men who are in a relationship. Luckily, my ex had the sense to stay away from me when I first told him to do so."

—Anonymous

10."When I was 18, I moved eight hours away, but my boyfriend and I stayed together. Before moving, he and a friend of mine ended up becoming friends during a class they had together. They had similar names and the same birthday, and my friend was telling me all about this. I had my suspicions, but I left it alone because I trusted my boyfriend. Fast forward a few months. I moved away during the summer, and the relationship got rocky. I had a gut feeling, and on New Year’s Eve, we FaceTimed for the ball drop. My friend was in the background of the FaceTime and everything was denied. They said they were just hanging out. A few days later, I asked my boyfriend's best buddy if something was going on, so he called me and laid out the whole story of how my friend jumped my boyfriend on his buddy’s couch. I called him immediately freaking out, and we broke up."

"Over the next few weeks, rumors reached me that they had actually been seeing each other for about six months (since before I moved). They didn’t last, and I’m gay now."

shyraanichole

  Aleksandr Zubkov / Getty Images
Aleksandr Zubkov / Getty Images

11."I dated my ex for four years. I just happened to find out through a very weird grapevine of mutual friends that he had told all of his friends we were in an open relationship, and he had a full-blown relationship going on the side for the last year or so with a female friend of ours. We went out with her almost every weekend. He would have her over and sleep with her in our house that we bought together. When I finally found out, of course he cried and cried and begged me to stay. I did not. When I confronted her, she pretended she thought I knew about the relationship. They are still together.

"One thing they were right about is that they are a much better fit. I’m doing great now and feel closer to myself than I ever have. I genuinely worry for that girl because I can’t imagine having such low self-esteem and picking THAT kind of man to be your partner. She’s a horrible person, but I still hope she makes it out before he inevitably discards her. That’s going to be really embarrassing for her."

—Anonymous

12."I had a best friend in San Diego who needed a place to stay. My husband and I had transferred to San Francisco from San Diego. When she called me to say she needed a place to stay, I said of course. She moved in and they proceeded to resume their affair. I found out when her 'friend' from her workplace called and clued me in. You should've seen their faces when they came home to their bags packed."

—Anonymous

  Bernd Vogel / Getty Images
Bernd Vogel / Getty Images

13."I was in the Navy at the time and had been married for just over five years. I was currently on shore duty, so no deployments or anything in the previous year or so. Things weren't the greatest in the marriage, but things seemed to be holding on...or so I thought. We were planning a week-long road trip with my buddy, who was also my supervisor. A bunch of us in the shop were into beer brewing, and we planned to hit as many craft breweries as we could. Just before the trip, we had a big argument, and she was all over my buddy. It turned into a grade-A cluster, and we ended up separated by the end of the night."

"She stayed over at our mutual friend's house where the get-together was, and I headed to our house (a block or so away). Next morning, she gives me the 'I don't love you the same way any more, and I have feelings for your buddy instead' speech. At that point, we were all mad, and I told her to get out and do whatever the hell she wanted to do. So, they went on the road trip while I stayed home and dealt with my anger. I had some time to think about things, and I realized that the relationship had been going down hill, and I pretty much got to a level of acceptance with it.

End of the week, they get back. He's sitting there apologizing in tears, she's explaining that it wasn't intended, and I'm just at the point of 'take your crap and leave,' so that's how the night ended. Next Monday, we're both back at work. He's still my supervisor, so we are dealing with that. Our higher-ups were told what was going on and offered to transfer one of us, but we declined. We decided that home was home and work was work, and we would let them know if it changed.

Now the fun stuff! The divorce started. In California, at the time, there was basically a six-month period between filing and finalization. We worked together that entire time and even attended functions at other friends' places, etc. Overall, the divorce was amicable, as we both realized there was no hope of trying to keep it together. Heck, for most of that period, the majority of our coworkers still had no idea what had happened. We kept it from becoming a huge conversation item.

Some of the key fun bits that happened during that six-months: She called and asked if they could have the dresser that I kept so they could have the matching set. I said sure, but I needed a dresser, so they cleaned up the one he had and we just swapped them out. I bought a car that needed to be towed, so I borrowed his truck to run it home overnight and we swapped cars for the day. Once they started planning a wedding, he found out his brother wasn't going to be able to make it out, so I was asked to be an alternate for the best man in the event he couldn't get someone else. Yes, really. Another person volunteered. I did house-sit for them while they went on a honeymoon. She took the dog and I could watch the dog without any trouble, so I did that. Her mom had moved in with us earlier that year and still lived at my house for another two months after the divorce was final.

Shortly after their wedding, he got transferred to another ship, so I have no idea what happened after that. We were fortunate that we didn't have kids, so there was no reason to ever speak again. Haven't talked to them since (that was in 1995). Couldn't even tell you where they live nowadays. So, I went through the betrayal/loss of trust period, but ultimately managed to get through it and am now happily remarried (about to hit our 25th anniversary). A good learning experience."

—Anonymous

14."Found out my boyfriend was sleeping with my (then) best friend when I snooped through his phone. I had only recently given birth to our child, and intimacy was a struggle. I had a feeling he was being unfaithful, but she kept telling me I was being ridiculous and that he loved me. I trusted her. Turns out she was using him to get to me via a three-way, but I ghosted her and I still live with the boyfriend, as long as he shares his passwords with me."

—Anonymous

  Martin-dm / Getty Images
Martin-dm / Getty Images

15."My mother and the love of my life/my first love/the guy I gave my virginity to. Turned out they had a two-year affair that started before I went to prison, then I went to prison for one year and my mom started acting jealous when I was around the love of my life. I found out officially (because everything was denied) because my mom didn't know how to erase the trash off of her phone, and so I saw the message, 'Better not let your daughter find out.' We had gotten our phones at the same time, so it wasn't an old message. Then, I started dissecting and going through everything. I told my mom that I knew, so she told me the truth, but downplayed it all."

"Since that day over a year ago, I no longer talk to my mom. I tell everyone she died, because to me, she did. And, I'm still with that guy. It's been a bumpy road. My self-esteem is gone, and because of that, I've gained so much weight. I started drinking bad. But, somewhere along the way, I found the strength to get sober and put my son first in my life."

—Anonymous

16."This was in high school (15+ years ago), and I was talking to this guy. My BFF at the time knew this guy too (small town). Anyways, this guy would text me on lunch breaks and after school, and we'd hang out on weekends. Next thing I know, my BFF says she's going to prom with him and it apparently wasn't a big deal because he and I were just 'talking.' A week goes by, and we realize he's lying to us both and we drove to his house to confront him. She goes in and I wait in the car like an idiot. Well, 30 minutes go by and I go home. They were hooking up. She went to prom with him (obviously I never talked to him again). Mutual friends lied and told her he had herpes."

headsup7up

  Hill Street Studios / Getty Images
Hill Street Studios / Getty Images

17."Best friend and boyfriend. I had suspicions, but they both gaslit the hell out of me. For example, my best friend argued with me during an episode of Jerry Springer that it’s not really a bad thing to do to someone, that the friend should be forgiven if it happens, and that I was 'crazy' for not forgiving the friend (hypothetically). I also opened a naked Snapchat picture of her on his phone, and my then-boyfriend argued with me that she obviously meant to send that to someone else and that I’m a bad person for not trusting them."

"Both told me I needed therapy, but months later, he finally admitted they were sleeping together. When I confronted her, she told me she did it because I wasn’t there for her enough during a breakup she had (even though I was struggling dealing with a miscarriage during that time and supported her in other ways, like providing a place for her to stay at during campus off-times), and she told me I wasn’t really her best friend (clearly). She then turned our entire friend group against me saying I was actively stealing her man, even though I had been with him since before I knew her. The whole situation gave me so much anxiety, I dropped out of school for five years. People are trash."

—Anonymous

18."I just found out my spouse cheated on me with their best friend. At the time my spouse and I first started dating, they would come home from work with scratches on their back. They blamed the material of the shirt, but they wore an undershirt. They would also tell me a certain colleague would 'scratch' their back. But these scratch marks looked like scratch marks from sex. I was 18 and naïve. This wasn't the first incident. My spouse and their best friend were apparently screwing around behind my back since before we got married, all throughout my pregnancy, and up to five years ago. I just found all of this out a few weeks ago, and my heart shattered."

"My spouse promised me they would be my safe person, as I'd been cheated on before. To find out that 25 years have been a lie is gut-wrenching. We have children, and I honestly don't even care anymore. I'm done. Due to certain reasons, we cannot, at the moment, afford to move away from each other. I know there have been a few other people they have cheated with on me with, and throughout the years, I've just become numb. And yes, all these people they cheated with were our mutual friends. I've already cried, gotten angry, grieved, and now I'm just super 'whatever' about it. My spouse and I no longer have any sort of relationship and we don't talk to each other. We have a huge house, so they stay on their side of the house and I stay on my side. I no longer speak with these 'friends.' I'm simply living my best life, doing my best to move forward, and maybe someday I'll meet someone."

—Anonymous

  Aitor Diago / Getty Images
Aitor Diago / Getty Images

19."It's been a couple of years now, but I came home from work one day and my lady of 25 years was gone. Last thing my son and I heard from her was that morning when she told us she loved us and she would see us that afternoon. I ended up having to file a missing persons report and say my truck was stolen. I finally found her in the next county with my little brother and some of his friends. I questioned them and both said nothing was going on, but I had that gut feeling. One night, I picked her up so we could talk. We came back to the house, and that's when she broke down and told me they were together."

"At about the same time, I heard him come in my back door. I'm a big guy; I'm 6'1 and 300 pounds, but my brother is 13 years younger and bigger. Regardless, I threw him out the back door with one hand, then again off the porch, and treated him like the fool he is all the way to his car. That situation has put a big hurting on our family. Of course it didn't last long at all, and he's sitting in jail right now."

—Anonymous

20."A coworker’s boyfriend cheated on her with another coworker. The boyfriend conceived his child with said coworker in the janitor’s closet after hours (the boyfriend also worked with us and was the janitor). The sad part was management set this in motion by hiring the coworker he cheated with a second time (they fired her only to rehire her again, and that’s when she got pregnant). The coworker who was cheated on is a long-term employee of the company who was treated like crap by management because they took the pregnant coworker’s side due to her being young and vulnerable. Six years and two more kids later, the coworker and her boyfriend are now married with the past behind them and a stronger relationship."

—Anonymous

  Ronniechua / Getty Images
Ronniechua / Getty Images

21.And: "He cheated on me with his 'girl best friend,' the one he told me not to worry about, who he'd been friends with forever and said they were just super close. Turns out all of those photos together were actually WHILE they were a couple. She had been happily sharing their relationship all over social media and just wasn't tagging him. In the three years I had been with him, he had also been with her. She got to meet the family, the friends, etc. They even bought a HOUSE together. Lessons learned. Do the internet searches before falling in love."

—Anonymous

Good grief. These stories make me feel sick. So sorry to everyone who was treated unjustly. Do you have a similar story you want to share? Feel free to vent in the comments.

Note: Submissions have been edited for length and/or clarity.