Sacramento Skeeball

Immediately before a man ejaculates, he pulls out and keeps his penis at vagina level. He then shoots his wad on her, and for each load that flies out he receives the corresponding pointage: the navel area is 10 points, the chest 20, the head 30, and if any lands in her mouth he receives 50.

You straddle your partner and jerk off. Various points are assigned for hitting locations on the other persons body (eg., 10 points for boob, 50 points for mouth, etc.)