Sex on a shelf or "shelf sex" tends to be a guy-girl pairing in a sort of FWB relationship. In this case, the guy can hit up the girl any time and she is always there for sexual activity. Basically the best thing for any horny guy. Similar to a booty call.
Jessica said that her and Michael were friends with benefits, but she was just sex on a shelf to Michael. It was basically all about him.
by pseudope3 May 30, 2017