I think my boyfriend might be gay, I need some outside opinions

We've been dating for 9 months and just moved in together. In the beginning of our relationship we had an active sex life and it slowly died down from a few times a week to once every two weeks if I'm lucky.

My really close friend happens to be his ex, I asked her if she experienced the same thing. She said yes, along with every other girlfriend of his.

We've been able to communicate about this problem him and I and he feels really bad and it makes me upset that I can't have the active sex life that I want in a relationship. He knows this is a huge problem for our relationship. There are many nights where we both go to bed upset. I'm scared to even make a move on him now and this doesn't feel healthy.

He can't explain why he starts off a relationship with lots of sex and then it dies down. He says he simply just doesn't want to have sex very often.

I've searched causes of loss in libido and drugs and alcohol may be a factor and well he is only 17 so perhaps there's more to it than that. (I'm 24 so already our relationship is a bit out of the ordinary and I have different expectations than he might but that's perhaps besides the point) ...

But what made me go on to think about the possibility that he may be gay is first, when he does want to fool around, he pushes for anal and likes that particular area. His ex confirms this fact. Second, we have just moved in together. I was cleaning the other day and found a vibrating butt plug (not very hidden either surprisingly).

That got me wondering. I mean he does happen to pay more attention to the way he dresses than most 17 year olds. But I know his character and if this is something on his mind, he has a lot of boundaries to cross with himself before he can even admit it to himself. He puts up quite the tough guy front but is a big softy underneath.

Anyway - I'm not quite sure how to go about this. I don't want to throw question at him. *IF* he is curious about that lifestyle, I believe he will approach it at his own speed.

but now I'm stuck with this thought in the back of my mind and it will probably be there next time we fool around. So my own state of mind will be altered from this point on lol see what I've done to myself.

I want to be supportive of him no matter where we end up in life. And I'm sure he would be supportive of me in that same sense. We work well together that way. Just now there seems to be a rift in our communication and i feel distant from him. I want that space between us to shrink.

My sex life isn't what I want it to be. Any advice on how I can go about creating an open communicative relationship with my boyfriend that will benefit us both no matter which direction we take?

If anybody actually took the time to read all of this I thank you so terribly much. Any thoughts?

<3