So I've quizzed you about whether it's healthy or not to skip out on wearing undies during the day. What about at bedtime? Personally I like wearing underwear to bed, but my Grandma always said "Don't wear underwear to bed. You've got to let yourself air out down there." Is my Gram right? Does your crotch, um, need to breathe?
Here's the deal. It's basically all about personal preference. If you've never had a problem wearing undies to bed, then I say keep doing what you're doing. I'd stick to cotton undies, though, since this material is breathable. Wearing tight underwear or a pair made from polyester or some other material that doesn't breathe can lock in moisture and lead to yeast infections.
On the other hand, if you love to sleep without underwear, then going panty-free is okay, too. Just do what allows you to feel the most comfortable.