Gavin Boner

A gavin boner, is the build up of cloth on ones fly (trouser zip) due to the rigidity of the zip. It appears that the "fly user" has an erection, but it is a very small erection, hence, gavin boner.

Dude, look at that guy's gavin boner, it's pretruding like a whore!

by thebumrecordings October 29, 2008