Having sex with a random girl doggystyle and you pretend you're done then you smack her in the vagina with a hand full of Mayo and throw her off the bed screaming that your real name is "Roger Clots"
When an Irish man has sexual intercourse with a woman until he is about to cum, and then stops. The female then clinches her vagina to make the mans penis explode.
No longer only for the Irish, but received it name as it was traditionally preformed by Irish woman who no longer wanted children from their husband.
patty- Irish
mayonnaise- Because that is all that is left afterwards.
My wife said she doesn't want any more children, I am afraid if i do not get a vasectomy she will give me a patty mayonnaise.