When you are banging a girl/guy and right before you blow you pull out and jizz into his/her bellybutton and then take one of fingers on your RIGHT hand and push it in and out of their bellybutton so it makes a noise.
I was banging that chick so hard last night and right before i blew my load in her I pulled out and gave her the old, greasehole and she loved it!
A subspecies of gasshole. A greasehole is a person that exhibits many similar qualities of a gasshole, those being burping and farting considerably more than average, with the added bonus of just being a greasy fuck. Will often have greasy hair & oily skin, eat only greasy food, grease stained clothing and/or all of the above.
Mitch: "I gotta stop eating so much fast food. I'm sweating in places I really shouldn't be sweating in."
Ricky: "You're such a fucking greasehole."