Jerk off a Hot Cock

I love it when a man lies completely naked in bed next to me with a morning erection. We were at a party and went to the room together at night and ended up in bed. Now I'm horny for this cock again and I'm jerking it off - so that the guy gets even hotter and hornier for me and then later fucks my wet pussy. But somehow I can't quite manage it. What am I doing wrong...