Gah, I've made so many threads and it seems wrong for me to constantly make some more. Anyway, in my new school this one kid keeps patting me on the shoulder and back. I guess he felt a kind of bump where my binder was and keeps doing it to kind of see what it might be. If he asks, or if other people start doing it, I don't know what I should say my binder is. It ends at the mid section of my back, so I can't say it's a tank top. I can't say it's a man bra because I'm really thin and skinny. So, what should I say?
I'd go with, "none of your business." As far as I'm concerned, what's under your shirt is your business, be it a binder or a bra. If all else fails, tell everyone it's a back brace and make up a heroic story about a back injury until additional opportunities arise.
Tell them you have gynecomastia, and it is a chest binder to keep you from looking like you have breasts. You don't have to be overweight to have "man boobs." Some men develop them anyway.
stick with the back brace. I wore one when I was younger because I have scoliosis. So you can just say you have scoliosis too and that's why you wear one! (if they ask, of course none of your business is always a good answer too)