The 22-year-old make-up mogul and Travis, 28 - whose daughter, Stormi, was born in February 2018 - came together for the annual holiday, with Travis being invited by Kylie's family on a trip to Palm Springs.
An insider told E! News: ''They all stuck together at one table before Khloe [Kardashian] went over to join her friends for a game.
''Kylie and Travis then got up together and got drinks. They were strolling slowly, watching some of the table games, and were followed by Kylie's security.''
Kylie and Travis split in October - but rumours have subsequently suggested that the high-profile duo may be about to rekindle their romance.
The eyewitness added: ''They seemed very close. There was no PDA or anything romantic, but they seemed happy to be together. They whispered in each other's ears a lot and laughed.
''They were having a good time. They all headed back to Kris's house for the night.''
Meanwhile, a source recently claimed that Travis ''still loves'' Kylie.
Travis - who dated the brunette beauty for two years prior to their much-discussed split - reportedly still has feelings for the 'Keeping Up with the Kardashians' star, although he thinks their romance was a case of ''too fast too soon''.
Explaining Travis' outlook on their romance, the insider explained: ''[He] feels that their relationship was too fast too soon.
''He loves her, but he wanted to be able to live his life and travel and be with other people and not have to worry about always going back to his family.''
What's new in the music world this week?
Watch three incredible live performances from Discovr.TV.
Don't miss the K-pop titans' return to Europe.
Listen to Alex Bayly performing 'Animal'.
Two weeks ahead of Independent Venue Week, Dry Cleaning made 'Britain's Best Small Venue 2015' (NME) the second port of call on their 2020 tour.
'Leave Home' was released on this day (January 10th) in 1977.
For their last gig of the year, The Libertines came back to their adopted hometown of Margate to finish off their latest tour.