This can be hard to manage. I'm a lesbian myself but had no idea about it for a long time. Being asked about it outright before I'd figured things out definitely fucked with my head a little bit. I grew up in a conservative household so the idea that I might be gay just put me into a sort of fear over it and I didn't end up finally sorting my shit and dealing with it until I was 24.

I don't mean to scare you, but just be careful about how you go about this. I wouldn't ask him outright. And don't be too obvious about it, but if you're okay with it, just do whatever you can to make him know that you're fine with it and will love and support him no matter what. If it's a thing, he'll come to you eventually. But don't push him because he might still be trying to figure it out for himself. My mom asked me about it a time or two when I was younger, and I know she was trying to let me know she would be supportive (my dad was the one I had more to worry about with that), but she definitely asked about it before I knew anything myself. She wasn't the only one, though. A friend's older sister was the first person I can recall suggesting I was gay, and I was 11 at the time and not really thinking about that kind of thing yet. Once did I start to recognize some of my thoughts/feelings as being gay I had a long time where I was uncertain if it was a gay thing or if the idea had just been put into my head by having people suggest it.

I realize now that was not the case, but when you're young and scared it doesn't take much to throw you off. This is way too long. All I really needed to say is that you shouldn't come to him about it directly, but just make sure along the normal course of your day (don't make it too obviously shoe-horned in) that you'd be fine if he was gay. And then just let him come to you.