"He’s always been nervous about turning his back on the family for too long, out of fear that he’ll be frozen out or replaced by someone else.”
Sofia, 21, and Scott, 36, are said to have reached an agreement and plan to split their time in each city.
"Sofia’s thrilled and Scott’s cautiously excited, if still a little nervous,” the source concluded.
A change-up might be a relief for Sofia, who hasn't felt secure in her relationship when in the presence of Scott's ex, Kourtney.
During a recent episode of Keeping Up With The Kardashians, tension arose when the trio went on their first trip together. The vacation ended in disaster, with Sofia claiming Scott acted “less mature” around her than he did with Kourt. She also said she felt "left out"
"Sofia mentioned to me that I'm acting a little bit differently around Kourtney. It's tough because sometimes Kourtney and I have so much history and have known each other so long, so I've just been trying to be kind of mindful and not make Sof feel uncomfortable just because Kourt and I have known each other our whole lives," Scott told Kim over the phone.
He added that the stress of the situation has caused him to lash out at the mother of his kids.
"Now I'm kind of - I'm not being rude to Kourtney -but it just puts so much stress on me and then it just turns into me being not happy," he confided. "I'm not even fun to be around for anybody. I think this trip out of the other trips we've been on has a little bit more pressure because there are camera crews everywhere."
Surprisingly, Kim took Sofia’s side.
"She seems like she's pretty cool with everything. So, if she's speaking up about something that bothers her, you kind of have to pay attention. And Kourtney has to completely understand that. Don't get discouraged and be unhappy. You guys will figure it out."