Is it unhealthy not to wear underwear?
Well, according to my extensive research, it seems that underwear is not an absolute health necessity; airing out your privates is not as dangerous as playing in traffic or something. There are, however, some practical and health benefits to wearing undergarments.
Underwear protects you from dirt and other irritations in much the same way that your pubic hair does; underwear also helps keep you warm. On a practical level, underwear is also a good idea where the cleanliness of your clothes is concerned, putting a layer between any vaginal discharge or odor and your outerwear.