This phrase is used when a person like to convince other person to cheat on her\his boyfriend (or girlfriend).
Guy: Hi babe, Can I have your phone number?
babe: Sorry, I have a boyfriend.
Guy: boyfriend is not a wall ! !
babe: Sorry, I have a boyfriend.
Guy: boyfriend is not a wall ! !
by Yaron7 May 2, 2005
Get the boyfriend is not a wallmug.