Underwear offers a barrier that keeps residual urine and feces particals from absorbing directly into your pants.
People that dont wear underwear let their bodily fluids make direct contact with their pants, and then expose them directly to any surfaces their bits might touch.
Not wearing underwear is unhygienic.
Now I’m really curious. I’m not a native English speaker. If you call underwear pants, what do you call what’s over your underwear? Trousers maybe?
Trousers.
If they are trousers, what does it mean to “trouse”?
Opposite of dogging, mayhaps?