While bending over like you were in a downhill skiing contest, you reach back and jerk two dudes off. In front of you, you are blowing a third guy. A fourth guy is optional, but that would require vaginal or anal intercourse. Also, you'd be a whore.
I need new friends. After we went Downhill Skiing with that girl, I haven't been able to look them in the eyes. But boy was that handjob good.