After having sexual relations with a man when he cums on his partner's stomach and most of it gathers inside the partner's bellybutton.
"Jane, what's that in your bellybutton?"
"Oh phooey, that's from last night when Todd gave me a cumbutton."
"Oh phooey, that's from last night when Todd gave me a cumbutton."
by Evan Vanderhoff November 11, 2016