Kourtney Kardashian says her tension with sister Kim Kardashian is "ongoing."
"I think it started at the end of Season 14, a lot of tension building between us," Kourtney said. "I felt like every day almost I was being picked on and criticized and I just couldn't take it any more."
Kourtney said she's still working out her problems with Kim and their sister Khloe Kardashian.
"Honestly, I think it's ongoing," the star said.
"I've really been working on myself a lot and I think through my growth, I'm better at expressing myself. I think in the past I've always been great at like not being emotional. I think that I'm better now at expressing my feelings.""It's a lot of communication instead of letting things go back into the way that they were. It's definitely a process and you'll see it throughout the season," she added.
The promo showed Khloe getting a phone call from a crying Kourtney after the mom-of-three clashed with Kim over the schedule for a photoshoot.
"Khloe, you don't say things like that," Kourtney said of Kim's remark.
"You guys just have really different values than me. I choose to be a mother to my three kids. I'm not here looking for another job. I already work enough, more than I would like to."
Kourtney's call with Khloe was interrupted by Kim, who went off on her sister about their scheduling conflicts.
"You're a very distraught, evil human being. I don't want to see you, okay? I don't agree with who you are as a human being," Kourtney told Kim. "I'm not going to live my life around people that make me feel not good on a daily basis."
"Keeping Up with the Kardashians" Season 15 premieres Sunday, Aug. 5.