GuyRule #9.0: Farting (to Fart)
"Again, depending on your relationship with the guy, the Guy Rule is you can't fart too soon. Usually somebody whose in their car, if you're riding in the car, or in their house, it's acceptable to fart only after he's farted in his own car or home. Okay, farting in his car before that happens is very unacceptable. That's a complete breach of the Guy Rule. You have to wait for the guy to fart in the car first, then you can fart. That's the Guy Rule.
Now, when you're outside, it's quite acceptable to let one go, regardless if you know the guy or not. The sooner to let one go if you don't know the guy, the sooner you know if this guy's cool. It's like letting him know like animals that you let one go early; you kinda let the guy in, like, heh, you're cool, man, you're in. We're on farting term early on." -G