pretty much what the title says. my (25NB) fiance (29 M) fiance has a crush on my (22F) girlfriend. he knows she's a lesbian, but he still can't shake the feeling of attraction, and in turn, jealousy. he's made it clear that he has no problem with me being with her, he just wishes he could get some love too.

he wants me to tell her how he feels so he can just get it out in the open/stop feeling like he's hiding something, but I can't help but worry he's gonna be heartbroken when, suprise, she's still a lesbian. and we've had this talk. but he still wants me to just tell her "so she doesn't find out on accident and feel awkward" but I feel like telling her outright would also be awkward?

I'm not sure how to proceed here, because my fiance and I have been together for 7 years and my gf and I are only a month in, so if anything has to change he will always come first, but he doesn't want to drive a wedge between me and her.

should I tell her? if so, how should I go about it? obviously I'm not gonna be saying it in a "you should date him too" kinda way, but I don't feel like it's fair to put this on her. I also don't know how to help him get over this crush he has, it's just not going to work, you know? and he knows that, but I can tell he's holding out hope that I just don't think is worth holding onto.

please be kind, he may be misguided, but he is a wonderful man otherwise.