Sources close to the former couple tell TMZ ... Kylie and Travis are getting very comfortable together since their split, and he's been spending lots of time at her house -- something we're told will continue.

We broke the story ... Travis dislocated his knee after falling onstage at Rolling Loud, and now we're told the injury is one of the reasons he's been holed up at Kylie's crib in Calabasas, where he's mostly hanging with Stormi.

We're told when he's not at Kylie's main crib ... Travis is spending nights at the home he and Kylie shared in Bev Hills.

Our sources say Kylie and Travis are maintaining a friendship, and over the next few months, they plan on spending even more time together with Stormi because the holidays are fast approaching.

Those plans are already in motion ... as we've reported, Kylie and Travis took Stormi to a pumpkin patch earlier this week from some good ol' fashioned Halloween fun. But, it was telling the parents only took pics with their kid.

As of now, our sources say the plan is to celebrate Thanksgiving and Christmas as a family, and the goal for Kylie and Travis is to keep things familiar for Stormi with family parties and events including both mom and dad.

And, get this ... while Kylie and Travis aren't currently a "couple," we're told some of their friends believe the exes will get back together by the end of the year. Remember, there's a little bit of a pattern here ... break up, make up, break up, etc.