Taylor Swift and Travis Kelce couldn’t keep their hands to themselves Saturday night … lockin’ lips at Neon Carnival after engaging in some backstage PDA.

Video from inside Neon Carnival — an invite-only rager sponsored by Liquid IV, Patron El Alto and Levi’s — shows the power couple immersed in their own little world, lips securely locked to one another.

Looks like they’ve both got drinks in hand at the mega-exclusive event … though they’re far more focused on using their mouths in a different way to take a swig.

BTW … an eyewitness from inside the event says “Vanderpump Rules” star James Kennedy was DJing at this moment — unclear if his music helped set the mood.

The couple started early with the PDA … sharing kisses and dancing backstage while cheering on Tay’s longtime collaborator Jack Antonoff and her pal Ice Spice.

It’s a bit surprising to see Taylor and Travis at Coachella this weekend, to be honest … as you know, many people thought they might skip this weekend after staying in L.A. for a sushi dinner date Friday night.

Instead, it seems they decided to make the most of their few weeks left together before Taylor goes back on tour … partying into the early morning hours alongside a gaggle of celebs.

BTW … just a few stars who hit Neon Carnival this weekend — Paris Hilton, Simu Liu, Tinashe, Kesha, Amber Rose, Jon Batiste, Madison Pettis, Harry Jowsey, Kyle Richards and many more.

As for whether Taylor and Travis noticed anyone else at the party, given their makeout sesh … we’d guess it’s not likely!!!