(verb)- To hook up with a person in the top bunk of a bunk bed. Can be modified into a double-bunk if there is another couple hooking up on the bottom bunk.
Person 1: "Yo, you here about that kid who top bunked it at ski camp?"
Person 2 "Yeah man, that is just gross! I hope he washed his hand after"
By Meris
Top Bunk
The act where a male assumes the top position during the sexual act of 69ing, opposed to the usual bottom position where the female is on top. This can be also referred to as “calling top bunk”, and “top bunking” if used as a verb.
She wanted to 69, but she is bigger than me and would crush my face, so I called top bunk.