The act of blowing semen received in one's ass pursuant to anal sex on the other person's face in a show of disgust with the overall pleasure received from the act. Can be distributed with a fart or shit, and is best done when the other person is least expecting it.
My boyfriend wanted to try anal for the first time, but I couldn't get off because of his pin dick, so I gave him an ass bukkake. He's in the shower right now, but he won't come out clean.