Only tell him if you think it will help you/you feel it's something you need to do. Don't go into it hoping he'll reciprocate, because chances are, he won't. You might be right about him, but if you go in with that hope, the odds are stacked against you, especially without any real evidence of his homosexuality.
That said, I think you should tell him!

as long as you dont set yourself up for disappointment.