Happy Birthday

This is a short story, it turns out that the other day I invited some friends to my house to celebrate my birthday, there were 7 friends and my girlfriend. We all started drinking in the patio while my girlfriend was doing things inside the house, obviously we got drunk and ended up all hammered, suddenly I woke up in the patio alone, it seems I had fallen asleep at some point but it was still nighttime. I went into the house as best I could because I was still drunk and going up the stairs I heard noises and murmurs. The door to our bedroom was slightly open, and there I saw my girlfriend getting with my friends, one was holding her by the pussy, the second was giving her a very hard anal that he had never let me give her before but the slut allowed it, the third was giving her oral and the others were sitting on the couch jacking off waiting to fuck my girlfriend. I stayed speechless when I saw that, a knot formed in my throat, but at the same time I started jacking off with that scene. I filled my hand with cum while watching them get with my girlfriend, they grabbed her hair, sucked her cunt and left her ass open. Finally I fell asleep sitting on the living room couch with my cock out and my girlfriend's used thong in the other.