Bobbin for cock 

When someone is sitting upright and keeps falling asleep. When their head bobs down and they jerk it back up, it looks like they're giving head. Bobbin for cock.

Joe must have been out late last night, because today in World History he was bobbin for cock.

Bobbin for cock by lectwistman August 6, 2009

Bobbing for Cock 

When someone is so sleepy their head starts to nod in a downward motion, as if they are giving someone a blow job.

Haha! Look at Jim over there. He didn't get any sleep last night so now he is bobbing for cock.

Bobbing for Cock by tatermctater April 16, 2015

bobbing for cock 

The act of bobbing your head up and down (almost sleeping) during a boring safety brief that is being given by a pussy officer. This usually occurs right before you get libbo.

pete: Check out that guy.
tom: Which on?
pete: the guy bobbing for cock...must of had too many drinks last night.

bobbing for cock by legitimate-jon September 20, 2013