Lived with a band mate for a few months and the 2nd weekend he was there I walked in on him and his gf absolutely going at it in Reverse cowgirl on the couch and was basically pointed right at me. She covers up but this dude keeps pumping into her and says "feel free to join or watch man. We're both into it if you are." So I pulled my cock out and she got off of him and blew me while he watched then she bent over to blow him and told me to fuck her hard. Then we just took turns on her mouth and pussy. I came on her face which made him blow in her pussy. This quickly escalated to her being a free use fucktoy for the both of us the whole time he lived there. A lot of times band practice would end with us passing her around. It was a fun 7 months