My girlfriend and I were having a threesome with another guy. I was on my back, she was on top of me and he was taking her from behind. At some point I slipped out due to not being fully hard anymore which I said out loud. Next thing I know is he grabbed my dick and started jerking me off. To my utter surprise it felt great and made me rock. He guided me back into my girlfriend and shortly after I pumped her full of cum.