When your significant other becomes horny at the thought of you, and the thought of them being horny at the thought of you makes you horny in turn.
Girl: Oh babe, your back muscles are sooo defined and it's turning me on.
Guy: -moan- (now erect, as counter-boner)
Guy: -moan- (now erect, as counter-boner)
by LufffiStudios July 25, 2013