Imagine you are fucking this qt from behind with her tight ass squeezing your dick, her flexed, clenched butt cheeks rubbing against it and everything, and suddenly she yells "UH OH! DAME! PURU OUTTO!" And you pull your dick out of her anus but before it gets far from her asshole she lets out an enormous fart and you feel the wind from it on your erect penis. I don't know about you, but I'd involuntarily coat her ass with cum at that very instant.