get up on the head

1. Encouraging directive made by a male for a female (or male, if that's how you swing) partner to directly engage the head of the penis in either oral, vaginal or some other orifice-centered sexual act.

2. A derogatory exclamation made from one male to another as an insult, much akin to telling someone to "suck my dick".

1. Girl: "Ooh, baby, I am feeling so sexy right now....." Guy: "Well GET UP ON THE HEAD, girl!!!!"

2. Guy 1: "You need to get out of my face, man..." Guy 2: "GET UP ON THE HEAD, you fucktard!!!"