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 hosted 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.