Driving under the influence is NEVER a good look!
Partygoers said they saw the two arrive to the party together, but that wasn't all.
"[They] kept grabbing each other's hands and Diplo kept pulling Katy in."
After their many moments of PDA, Katlo headed towards the dance floor and hung out with a number of famous pals, including Girls' Allison Williams!
How super adorable!
Things probably aren't getting too serious for the two, but all that matters is if they're having fun with each other!