kim shocked as Scott Disick sleeps over at Kourtney's house.

On Sunday's episode of "Keeping Up With The Kardashians," the mom-of-three updates sister Kim Kardashian about her life without the father of her kids.

"He's like 'I just want my family,' or whatever and I'm just like, 'Well what are you doing to try to change your life?'" Kourtney tells Kim. "There's just a lot that would have to happen for him to get on a good path."

As the two sisters get into a deep conversation about Scott and Kourtney's relationship, Scott walks into the kitchen ... and completely shocks Kim.

"It would definitely be a process. Do you think you would ever forgive him and get back with him?", Kim asks her sister right as Scott enters the room looking for his car keys.

"I am like in shock. I haven't seen him in so long," Kim admits in a confessional. "He obviously spent the night and Kourtney didn't mention that he was there! I thought Kourtney was really strong and firm and now are they back together? What is he...I just don't understand."