cock on the brain
When someone puts it in your ear and you can feel it touch your brain so hard.
We were just hanging out and he put his " cock on the brain" ; it felt so weird .
Cock for Brains
An idiot, especially one who thinks almost exclusively about sex.
Bill: *Stares at some random chick's ass*
Dave: *slaps back of Bill's head* Yo, Cock for Brains, focus.
Dave: *slaps back of Bill's head* Yo, Cock for Brains, focus.