The act of grabbing the excess skin of your ball sack, lifting it up like elephant ears and slapping a girl in the face with your dick!
Branham - Thompson, what happen with that chick.
Thompson - She sucked at giving head so I gave her a trunk slap.
Thompson - She sucked at giving head so I gave her a trunk slap.
by ~BTR~ January 15, 2012
"I really must wear something more supportive than boxer shorts when I run. My penis is raw from all the trunk slaps. It sounds like two elephants high-fiving when I run downhill."
by fairycakesupprise August 15, 2016
When your girlfriend and/or wife is post sex cuddling and you roll over and whack her in the eye with your penis.
by Rezelka April 1, 2012