The first is Smurf Sex.
This happens during the honeymoon; you both keep doing it until you're blue in the face.

The second is Kitchen Sex.
This is at the beginning of the marriage; you'll have sex anywhere, anytime. Hence, also in the kitchen.

The third kind is Bedroom Sex.
You've calmed down a bit, perhaps have kids, so you gotta do it in the bedroom.

The fourth kind is Hallway Sex.
This is where you pass each other in the hallway and say, "Fuck you!"

There is also a fifth kind of sex: Courtroom Sex.
This is when you get divorced and your wife fucks you in front of everyone in court.