God, I need to post in here more. >< I can never seem to find something to say that hasn't already been said before, but when I do, I feel like I start to ramble. So I shall put my rambling in spoilers.
But first, a belated welcome to [Snivy Baroque] from another random member!
I can't say anything about acceptance from one's parents unless they're fairly open-minded (darn you, lucky people here with tolerant parents!); you're more likely to get acceptance from any siblings you may have, since they've likely seen most of the same things you have.
Granted (and I honestly agree with them a little on this), because of his age, they think it's likely a phase. He brought up the topic almost completely at random (but failed to keep it from being serious), and he acts with little knowledge of the community. It really just feels like he's exploring right now, and until another year or so passes without any changes (when he's 16-18 and he's actually thinking more with his head than his curiosity, as per the majority of my family's off-topic experiences), I doubt that feeling will change. But exploring is just fine with me; and if he comes to realize he's not gay? Our parents will probably be overjoyed, considering their aforementioned reaction.