"I feel really bad that anyone was ever offended. I feel really bad that this was taken such a wrong way and I genuinely feel like s**t," Kendall shared, as the two laid together in her bedroom.
The controversial commercial, which was first released in April and then almost immediately pulled by Pepsi, saw Kendall playing herself at a political protest and using soda to bring peace between racially diverse demonstrators and police officers.
The commercial was slammed for commercializing political protests and rallies, and trivializing the tensions between minorities and law enforcement in America.
For starring in the ill-fated commercial, Kendall took a lot of heat and she admitted to her sister that she had "no idea how I'm going to bounce back from it."
"I didn't even know what to do," she said of the initial negative feedback that she faced when the ad was first aired.
"This is the first time you've had a scandal," Kim said, trying to comfort her sister. "This is your first real experience with something like this. It's OK…. This is just gonna be the biggest lesson learned for you."
"It's really depressing and it bothers me every single day," Kendall said.
In a solo interview with the KUWTK cameras, Jenner began to cry as she shared her side of the story.
"I would never purposely hurt someone, ever. And obviously if I knew this was gonna be the outcome, I would have never done something like this," Kendall explained as she wiped tears from her eyes. "But you don't know when you're in the moment."
"I felt so f**king stupid," she continued. "The [idea] that I would offend other people or hurt other people was definitely not the intent. And that's what got me the most."
When the commercial first aired, sources familiar with Jenner's contract with Pepsi told ET that she was "devastated" by the backlash, adding, " "This is the first controversial campaign she has been involved with. Even though she had nothing to do with the production and the message of the campaign, she will be blamed for this since she is the face."
The source also told ET that the commercial was only slated to air overseas, not in the U.S., but it ended up making the rounds online. For more on the controversial ad, check out the video below.
Keeping Up With the Kardashians airs Sundays at 9 p.m. ET/PT on E!