What catches my attention is your reference to crossdressing which presents a complication to this conversation that I've encountered as well. Although my crossdressing experiences were in the distant past well before my breasts began to grow and I found myself curious about my wearing a brassiere. I was quite surprised to do a search and find discussions on that topic at a number of websites. That search eventually led me to this website. It was likely my fantasy life that included crossdressing when I was younger that contributed to my excitement about accepting my breasts and searching for brassieres that showed them off. The delicate balance of assuring that we're really men and that the only reason we're wearing a brassiere is because we must do so, doesn't leave a great deal of room for surprise and excitement over the fact. Yes, men who've lived with breasts and have come to acceptance will often comment about appreciating their breasts and even enjoying a bit of intimate play with their wives centered on their breasts. If I read between the lines of your post, it is likely your relationship with all of this and your conversation with your wife will be a bit different. I'm single... my nipples are not so sensitive that I have to wear a brassiere... I don't have problems with my back that require that I wear a brassiere... I'm able to hike and enjoy myself without needing to wear a brassiere. When I put one on it is simply because I'm tantalized by the presence of breasts on my chest... which may or may not be rooted in whatever led me to crossdressing in the first place. I know the reason and have touched on it here, but there is no need to repeat that conversation.
Yes, acceptance is important and this is a fine group of men with whom to have these conversations. I'm not inclined to say looking at your photos that you NEED to be wearing a brassiere full time, but if you feel you want to do so, enjoy yourself... full-time, part-time, with your wife, on your own. Free at last, as they say.
Below is a recent photo of what has become my favorite brassiere. It works and my breasts are happy.