The wiping of ones sweaty privates and smacking an unsuspecting individual across the face.

When someone puts salt on a wet napkin then jizzes on it and slaps another person right in the mouth (Boca for spanish people)

When your hand is sweaty and you proceed to slap someone on the throat .

When you catch the ejaculate inside of your cupped hand, then going on to slapping your sexual partner in the face, with your ejaculate covered hand.