I wear a bra about 95 of the time, night or day. Unless I take a shower right before bed, I usually sleep in one because it's just what I'm used to and I'm too lazy to take it off. In fact, for a while, if I tried to sleep w/o, I'd have dreams that I was somewhere naked! Years ago a roommate of mine commented how perky my chest was, but that my future husband was never going to be okay with me wearing a bra to bed. Turns out he is.
I wouldn't call them perky anymore, but I'm sure that's due to my age, my pregnancies and years of breastfeeding, gravity, etc.
And lucky me, I'm president of the visible nipple club. It's like two spotlights on my chest. On the upside, a lactation consultant once told me I had the perfect nipples for nursing. Woo hoo. Could I trade those in for thinner thighs please?