I virtually always sleep in the buff. I don't generally like having any sort of clothing on when in bed. I do occasionally dress up in my forms, bra and a nightie, just for an hour or two as I relax, but then I change because I don't want to risk damaging my forms. Seriously considering getting a set of forms that advertise they are safe for sleeping in - then I might wear them, glued on, and maybe a very skimpy nightie, on occasion.