The sexual act of gaping ones partners anus with your fist then proceeding to teabag there gaping anal cavity with your nutsack and letting the sphincter heal and close around the sack of nuts. then regaping the anus and removing the nutsack and dragging your shit covered nuts from the top of their head to the tip of their toes.
Mike: Dude guess what.
Alex: You're gay?
Mike: Yea, Ronaldo gave me the Manheim Steamroller last night. =]
Alex: AWH ME NEXT!! ;]
When you have passionate, crazy sex with the fat lady from The Practice. (Or one of her stature)
She performed a Manheim Steamroller on me last night.