My Girlfriend is worried her brother is gay?

I would not presume to make any guesses about the uality of a perfect stranger, and your girlfriend should learn to mind her own business too. So what if her brother is gay? He will tell her and his dad in his own good time. And if his dad is "crushed" by the news, it only shows that he is obviously still living in the middle ages. Either way, stay out of it and tell your busybody girlfriend to do the same.