In this game it is done a little differently, it does not mean that you can go out completely naked and walk like that. When you choose the exhibitionist perk, you can immediately dress more vulgarly and also not wear any underwear at all, later if you don't wear underwear long enough you get a new perk "comando" which doesn't allow you to wear underwear (if I remember correctly) .
you can't be naked going on the bus, if you're just in a location exploring you can be as naked as you want to be.
you actually can wear underwear now (you had all your underwear confiscated when you got that perk in previous versions), but its more of a "if you want to" if you're trying to seem sexy in certain outfits ig?