KUWTK: Kourtney Kardashian Considers Canceling 40th Birthday Party After Fight with Kim

Kourtney Kardashian‘s 40th birthday is off to a rough start.

In Sunday’s episode of Keeping Up with the Kardashians, Kourtney considered canceling her birthday party after getting into a nasty fight with sister Kim Kardashian while deciding what to wear to the big bash.

The drama started when Kourtney invited Kim over to help her pick out an outfit, and her sister wasn’t shy about voicing her dislike of nearly every option.

“This is so typical of Kim to hate on every single look that I have and tell me everything is ugly. She doesn’t have to be so hurtful, especially when I’m so overwhelmed,” said Kourtney, admitting that she felt anxious about turning 40. “There’s all this pressure surrounding this birthday and it doesn’t help that Kim is acting this way.”

Things only escalated when Kim found out that Kourtney’s stylist reached out to several brands and designers with whom she has built longtime relationships. During a FaceTime call to give her opinion on another dress Kourtney was considering for the party, she accused the Poosh founder of copying her style.

“Why do you keep on picking out all the same clothes?” the KKW Beauty and SKIMS mogul questioned.

RELATED: Kim Kardashian Calls Kourtney Kardashian a ‘Fake Humanitarian Hoe’ During Savage Fight on KUWTK

But Kourtney shot down the accusation that she copies her sister’s style right away. “I don’t know what you’re talking about. I’ve never dressed like you. I dress completely different than Kim,” Kourtney said.

In her confessional, Kim explained that she works hard to maintain close relationships with the designers she borrows dresses from, and she doesn’t think Kourtney appreciates that.

“I don’t think Kourtney understands the legwork behind this. I don’t think anybody understands. You have to really have a relationship with that designer. She has no idea how this works,” Kim said.

Days later, the two were still at odds, exchanging verbal blows via text message.

“She’s like, ‘You’re the biggest, ungrateful bitch,’ ” Kourtney read from her phone while talking to a friend. “So I said, ‘God, you’re such a petty woman.’ “

“You’re going to school to become a lawyer and help the world and these are the kinds of problems you have?” Kourtney continued before reading Kim’s response. “Then she’s like ‘You’re really a miserable human-being and you keep not understanding the issue because you all of the sudden turn into such a humanitarian and talk about the world’s issues which you’ve not contributed one ounce to the world.”

“She can say it, maybe after my birthday,” added Kourtney, becoming visibly emotional.

RELATED: Kourtney Kardashian Tearfully Admits She Has ‘Anxiety’ About Turning 40: ‘I Wish I Had More Time’

Kourtney then broke down in tears, admitting that between the fight and her anxiety about turning 40, she no longer wanted to have a party.

“I really don’t take it personally, I know it’s not something that I’m doing,” she said. “It’s just hurtful. It’s not just that, I just feel overwhelmed with my birthday and everything.”

“I just really don’t feel like myself right now and at this point I just don’t even feel like celebrating my birthday,” she continued. “I hate being the center of attention, I can’t stop crying, I don’t want to be around anyone.”

But with her sister Khloé Kardashian‘s encouragement, Kourtney decided to keep moving forward with the party. And just days before the bash, Kim found a dress she thought would be perfect for her sister: a one-of-a-kind Donatello Versace dress.

“Kourtney is really emotional these days and going through it. I’m still really upset with her and the stylist, but it’s not the time. I want her to look amazing,” she said.

And Kourtney couldn’t deny that the dress was perfect for the occasion.

“This dress from Kim is sexy and chic,” she said. “I think it’s definitely her peace offering, and I’m willing to accept it.”

And after the party went off without a hitch, Kourtney said she was glad she managed to put her uneasy feelings about turning 40 behind her to celebrate.

“I am happy that we ended up having a party. I feel so much love from all my family and friends,” she said. “You know, my life might not be exactly where I pictured it would be, but it’s much more than I ever imagined. I realized there’s no need to get caught up in the pressure of feeling like you have to have it all figured it out.”

Keeping Up with the Kardashians airs Sundays (9 p.m. ET) on E!