adj. denoting any activity that is exclusively to be experienced by a group of males (bros, men, dudes), meaning no females (girls, women, girlfriends) are to intrude upon its sacrosanctness. Similar to No chicks, just dicks.
Dude 1: Alright, I'm so stoked to go fishing later: just you, me, and the guys.
Dude 2: Right, oh, I forgot to tell you, I invited my girlfriend to go with us.
Dude 1: Wtf?! Dude, today was supposed to be penis only! We can no longer be friends.
Dude 2: Right, oh, I forgot to tell you, I invited my girlfriend to go with us.
Dude 1: Wtf?! Dude, today was supposed to be penis only! We can no longer be friends.
by Dr. Battas March 28, 2009
Get the Penis Only mug.