A room bong is the action getting high only by smelling all the belongings (particularly sheets) in a room in which weed is regularly smoked for a very long time.
Dude 1: *out of weed
Dude 1: hey man, I'm out of stock. You have some?
Dude 2: Nah dude, let's go to my place and do room bong.
A room bong is when you and you’re roommate share a bomg in the room making ownership of the bong 50, 50.
Who’s bong is this?
It’s the room bong so idk.