After performing anal intercourse, ejaculating over the buttocks.

to cum all over a womans ass after sex

The vaginal area of a woman who is heavily aroused and very, very wet. "Buttered" is added to the existing phrase whisker biscuit once it has reached a state of slippery wetness akin to that of something that has been buttered.

a guy cumming on a girls boobs

Pouring melted butter on your asshole while masturbating.

Someone with a nice shapely butt, thick and round, nice looking.

The sexual act of filling one's anus with butter then proceeding to shove a corn cob up the anus all while yelling "LOVE IS THE ANSWER"