So my brother is an interesting individual. He's almost 10, and I'm convinced that he's either flamboyantly gay or TG/TV. One fond memory I have from last year, my mother was going through stuff from years ago, and she found a pink fluffy bathrobe, very obnoxious looking, etc. She comes to me, asks me if I want it, I of course say no, my brother flounces in, I WANT ITTTTT! He grabs it and puts it on and proceeds to run around the house singing in a high pitched voice about how pretty his dress is, my mother running behind him trying to retrieve her bathrobe. It was a hilarious scene. But anyways.
My brother recently found this alpaca hat, aka a beanie with ear flaps, and the strings hanging down from the ear flaps are braids of yarn, and he's taken to adopting a falsetto and talking about his hair. Which he's done very often with blankets or whatever he could find. So I asked him if he wanted to be a girl. He said yes, I asked him why, and he said because I like it.
So. I'm wondering, could he be TG/TV? Either way, is there anything I should do? We have homophobic parents, and I've already given him the talk on gay people and how they're human too, don't hate, etc. He got that concept perfectly well, but when I tried to give him the "what if your sister wanted to be a boy" talk, he was completely lost. The father is starting to crack down on his girly qualities, as he's getting too old for it to be a phase, and I've no idea what to do. It's a perfect example of how girls can get away with masculine qualities [me] and how it never works the other way around.

Any advice would be appreciated.