My wife has always been reluctant to go braless. She will but only in certain situations. Her nipples do not stand up
so when she does goes braless, you're not going to get obvious pokies. Her 'objection' is size. She is a 34-A, but they are firm and full and come close to a small B. Part of it I'm sure was upbringing, but she will comment that she needs a bra to make her feel like there is something there. One observation I made and am not 100% sure she grasps, it that the bras she chooses most of the time, have cups that swallow her breasts and can make them appear smaller. Same with a bikini. I've shown her that a small tri-top is much more flattering than a regular 'cup' with lining. She has some bras that are sheer lace and two 1/4 cup (though it is very difficult to find these in small sizes).
On those occasions when she would go braless, it was never with light fabrics. Had to be black, navy, brown etc. She worried her nipple would show through the fabric. The first time we went to a clothing optional resort, as we were packing and dressing to leave, I suggested she not wear a bra for the drive home (about 3.5 hours). She agreed, but since we were at a clothing optional, we didn't pack much. She had a yellow tank top. She stood in front of the mirror a good five minutes trying to see if her nips were visible. In the end, she went without. We stopped at a mall in Tampa on the way home. She occasionally commented, but I think for the most part, it wasn't bothering her.
Fast forward to the last couple years. She's been wearing more dresses without bras, as well as shirts. Still adhering to the rules about light colors. On a recent trip out of town (when she's more relaxed), I suggested she leave all bras and panties at home (except what she was wearing as we left for the airport from her office). She agreed. She was much more comfortable. During a conversation about that trip, I was telling her that nothing terrible happened. No one called the cops. No one pointed and called her sl*t or wh*r* for not having a bra. She agreed and I can't remember the comment, but I said, "you've been saying how over the past few years, your nipples have lost 90% of their pigment, so even white I don't think would have been an issue. She agreed. The other day, we were going out and she asked me to iron a dress while she finished her hair and makeup. It was a nice black & white patterned lycra type material. She wore a bra as the place we were going as she felt it was not appropriate to go without, but as she put on the dress and I was commenting how nice (first time I'd seen it as she bought it the day before) it looked, she was looking in the mirror and commenting that she thought even though it was white, she did not think going braless would be a problem.
(she also bought a halter dress and was going to surprise me, but couldn't wait until such time as we went out, so she let me know she got it).
I suspect that I will be seeing more outings where she is leaving the bra behind.
Next step is to suggest one of those plunging halter style tops (example below) for a trip out of town, say New York or Las Vegas. A little over a year ago, we were going away and shopping. She tried one on and it looked great (got a boner right there as she modeled in the dressing room). She said it looked really nice, but she'd have to wear a bra with it.
??? I said they are not designed for a bra. Some comments back and forth and the top went back on the rack.
With her newly found 'freedom', things may change. Patience has gotten me this far, I need to be patient a little while longer.