Dear fellows:
I just can't stop laughing here... From the very beggining of this thread, I was confronted with the harsh reality:
There are actually three kinds of pianists: homosexual pianists, Jewish pianists, and bad pianists.
Well, bad news to myself.
Then, this milestone of history revision (such as "Shakespeare was four women", or "Bach's works were written by his wife"):
I'm sure I once read an essay on Beethoven which claimed
a) that he was black
b) that the Immortal Beloved was a man
Now, I want to get some serious. I think we talk about this controversy because there are, unfortunately, so much prejudice in our world yet. To myself, particularly, the fact that a composer/performer was/is gay or not interest as much as his eyes' color, or his pet's name. I have some friends that are gay, and this never did matter at all. They know I'm not, and we respect each other choice. I think it's strange someone can be "accused" of being gay. Sounds as absurd as someone being accused of being "black", or "vegetarian", or "hindu", or "pianist".
Prejudice and ignorance, that always walk close together, are a major problem of our world. Think about the last century, and see how many times this was a cause of horrible problems. Prejudice against jews, gays, blacks, communists, latin-american, older, women. Can't we just take it simple? "Mr(s). A is/isn't gay". Period. What else does it interest or must be discussed?
Finally, some words to ImBetter:
As some people told you above, your brother do this just to annoy you (in spite the fact that he's probably 50% right), but consider the fact that you don't have to get neither annoyed nor "infuriated", as you said. Sexuality is something, if you are 12, you will discover in the following years, and it's something very personal and exclusive. If you have questions or problems, talk to your parents, or to a close friend, or to a shrink. Don't trust this crazy people out here!

Play your piano and just don't mind about your brother.
Best wishes!