1) Donkey Punch: It's when you're doing it doggy style and before you orgasm, you punch him/her in the back of the head and they clinch up making for a great orgasim due to the tightness.
2) Gorilla Mask: You cum in the person's face and then throw pubs on their face.
3) The Poltergeist: Have sex doggy style, then you have a friend take your place and you go outside and wave at the person you were having sex with.
1) Not funny (IMO)
2) Vaguely funny (IMO)
3) Still can't stop laughing, and I read it five minutes ago