Keg Cap

Prior to ejaculating, the male will insert his penis into his sexual partners belly button. Upon ejaculating the sperm will fill the belly button 'foaming' out of the seal made by the penis and belly button.

Bro! I totally keg capped that chick last night.

Or
Babe just let me keg cap you!

Keg Cap by Heykiddo100 August 26, 2013

Keg cap cup trap 

A game, originating at The University of Illinois in early 2010, that is designed to increase the consumption of alcohol at a kegger. The cap of the keg, once removed, is pocketed by the host, later in the evening the cap is dropped into an unsuspecting victims cup. The victim is then forced to chug the remainder of his/her beer and is now in possession of the keg cap; which he/she will then attempt to trap another unsuspecting victim into the same glorious fate.

Jason: Troy, need to top yours off?
Troy: Sure, man.
Jason: Here, I'll pump for you. (Tops off beer and proceeds to cap Troys now full beer)
Troy: You motherfucker.
Jason: That's how you play the keg cap cup trap, sir, just making sure you got your $5 worth.

Keg cap cup trap by JayRose August 23, 2011