second hand drink

A beer or mixed drink that someone has walked off and left from a bar or a party.

1. Dean must be really drunk. He is drinking that second hand drink. Someone probably spit or pissed in it and is watching somewhere laughing.

2. That second hand drink has a cigarette butt in it. Do you dare me to drink it anyway?

second hand drinking

when a sober person pretends to be drunk or acts stupid among drunk people

is that guy drunk?
no, it's just second hand drinking