Hey !
Honestly, I don't know the feeling, and since you've been dating for a year, it must be difficult to see that he doesn't seems attracted by you...
It might be hard to tell yourself that but, you should talk to him in the first place. Explain to him why this situation is difficult for you.
If he doesn't understand try to put him in your shoes, what would he feels if you were the one only looking at other men ?
I wish you good luck!