When I was much younger (pre 21) I wore a bra and on the occasions I went braless then I got terribly embarrassed if my nipples got hard, I had kids and I found the whole process of being pregnant ridded me of a lot of modesty - once you've had a room of medical students prodding and poking at you it toughens you up a bit and I found I became much more pragmatic about my body. I had kids and found searching for the bra I wanted in the morning was a waste of time, plus I'd always found them uncomfortable and constricting, so I stopped wearing a bra and haven't worn one since. My nipples are hard most of the time, it doesn't bother me, if someone wants to look let 'em, if they find them offensive they don't have to look. Nipples are a natural part of our body and in lots of societies they're actually on show most of the time, unlike a pussy nipples and breasts aren't something that are wholly sexual.