when playing beer pong, there is always left overs(backwash) in the cups needed to play the next game. The friends cup is a place to pour all the backwash, or "friends".
by sailboats September 25, 2007
Get the friends cup mug.A person you meet at an event or bar who is cool to hang out with at the time but you never talk to or hang out with again. A throw away friend.
by tocathe1 May 24, 2014
Get the plastic cup friend mug.