When two male homosexuals are engaging in passionate and libidinous fornication (in the assumed "doggy style", if you will, position) and the so called "pitcher" begins to feel a tingle in his jingle; and rather than warning his receiving partner of such situation, ejaculates into the preoccupied's comrade's asshole....whilst emiting last vocalized orgasmic moan (and the partner thinks his job is done, he can relax)..donkey punches the bitch.
"Man, i am going to snowdonkey him so hard later."
"Dude, i don't want to talk about it, but i totally got snowdonkeyed last night."
"I know the bruise looks bad, but i am a victim of the act of snowdonkeying. I, in fact, was a snowdonkey."