Watching your girlfriends walk off to go shopping together as your “friend” strokes your virgin ass and describes how, in the next hour, he is going to ram his ten inch cock up your tight ass.  You know that what he is saying is true and that you are about to become his cum dump, fuck toy. 

You are sad, because you know you will not be able to get hard and fuck your girlfriend again, after he cums in your ass.  As he slips his finger between your  cheeks and towards your hole, you notice that your cock has never been harder.