PUI

Partying Under Influence - like driving under influence (DUI)

So basically partying under the influence of alcohol or drugs

Me: Oh, hey! How was the party?
You: Oh... it was kinda boring since everyone was PUI. Just throwing up everywhere.

Me: Didn't you come to the party last night?
You: Yeah.
Me: How was it?
You: Weren't you there too?
Me: Yeah but I was totally PUI! Can't remember a thing!