Public Display of Underwear

I think about underwear way too often. Take for example my driving down the street, and questioning what the guy at the bus stop is wearing underneath his slacks. I'm not interested in the guy, or getting into his pants, I'm just really curious about underwear.

So when I had the opportunity to take public transportation recently, I was staring at crotches and asses looking for "panty" lines. Though that doesn't sound right for men. And if I couldn't see anything, I'd glance at the whole person and try to figure out their style.

I'd doubt it works, but it's rather funny to picture some guys in tight bikinis.