Rarely after sex. I'm worried about sagging my breasts over time so a bra is a must. I also prefer guys to wear something. I honestly believe that keeping privacy and giving privacy is essential to a relationship. I mean that we already had intimacy the night before...I don't see the benefit of waking up the morning after with a bare penis next to me. Having a bit of cover gives mystery and I like having that element.
I didn't until I was in a serious relationship. They convinced me to sleep naked (hehehehe). A little bit to get used to it, but I wouldn't go back, even tho I'm not with this guy anymore... and I sleep alone. Something really incredible about body heat and how it's just different with sheets rather than pajamas or a an undershirt or what have you, lol.
No, but my grandma does and one time when i spend the night at her house I walked into her room when she was just waking up and I haven't looked at her the same since.