The last time I intentionally went commando was an ill fated trip to Alaska in January. Tee shirt, loose Jean's, scokes and shoes. There was a foot gap at the top of the gangway and about 3 inches at the bottom. Not even heaters in the 100 yards between said plane and terminal. I did mention it was January and -17°f below with a windchill of about -20°f...
I've had a few times I had to go without underwear, mostly to school. I will forever hate the feeling and never want to do it again.
I tried it as a kid, but quickly learned that it's better to have a layer of fabric between my critical zone and that zipper. The pain of getting caught doesn't just go away.