Drinking Game: Public Displays of Affection

The vast majority of human beings are sexual. We have certain appetites and desires that long to be expressed through physical contact with other people. Kissing. Rubbing. Caressing. Some rated mature action on the side. It's all an integral part of human nature.
But as much as I accept this as a reality, I'm still somewhat put off by public displays of affection (PDA's). By no means am I advocating for outright censorship. I will freely admit that being on the receiving end of a PDA is fun. Yet as an unintended voyeur, I am equally perturbed by two sloppy drunks making out with one another on the dance floor at 2 am.
Drinking is possibly the one thing short of unconsciousness that allows people to endure a drunken PDA. In every crowded room, there is an uneasy amount of sexual energy buzzing around. Why not turn peoples horniness into inebriation?

The Rules:
(1) Drink every time someone hooks up with a random stranger.
(2) Drink every time someone places their hand on someones shoulder and lets it linger there for several seconds.
(3) Drink every time someone has another person backed up against a wall.
(4) Drink every time two people are holding each other at arms length, but not kissing.
(5) Drink every time people are staring at one another from across the room.