Whilst participating in anal intercourse, during the instant before the male ejaculates, the penis is removed from the anal cavity and shoved into the partner's mouth releasing the said ejaculation. The sudden removal of the penis from the ass, and the even quicker shove into mouth, shows position of authority which in turn arrouses the partner to immediate and legendary climatic orgasm.
Related term: double peti - same concept, but requires two male partipants and one very flexible and open minded female participant.
Did you peti that girl last night?
Yeah - I went straight ass to mouth on that hoe and pulled off the ultimate peti experience.
I think I blew her oh-ring out. I had to follow her around with a mop. It looked like someone spilled a five gallon bucket of mayo up in my casa.