so do most of my guy friends (which is about 99% of my friends). i dont really squirm at it though, for some reason i cant get bothered by that type of thing anymore.

It's like some deep, instinctual thing. If a guy tells you he doesn't do it, either he's screwed up in the head or he's lying.
You can stop yourself from doing it, but there's an unexplainable urge to sniff. Maybe it's some left-over piece of a past scent marking thing in the evolutionary tree. Who knows.