Why do some people always ALWAYS come out with this daft old chestnut?!
Of COURSE the OP (and any other woman in a relationship) wouldn't be bothered if the husband's shiny new BFF was 'male!' An extremely ludicrous thing to say!! He's not gonna fancy the MALE is he? And the MALE isn't gonna fancy him! If the MALE is gay, even if he fancies the OP's husband, the husband isn't going to fancy him back!
@Northoftheriver1 At this point I would be getting my ducks in a row. Your husband doesn't care about you or your feelings and how hurt you are. Don't be one of those married women who puts up with a philandering husband, who just 'gets on so well with women.'🙄 Your children are nearly grown, you can do better. And I don't believe ANYone who says they wouldn't care/don't care if their husband has a close relationship with a woman, that excludes them, where they have little meetings, and cosy, private little chats, and private messaging and talking on the phone.
From your most recent post @Northoftheriver1 it's clear that she is heavily into him, and he is doing NOTHING to stop it. Bastard!
Comments like the one I quoted, and 'you are mad at him for having a friend?!' can get in bin! As has been said before, it's never fat, 55 year old Nigel from Accounts is it, when a man gets a shiny new friend at work and spends lots of time talking to them, and getting emotionally involved?! 
As a pp said @Comedycook ignore the 'cool wives.' As I said, no WAY would they not be bothered in your position! It's OK to have 'friends' at work, even if they're the opposite sex. It is NOT OK for that 'colleague friendship' to spill over into the home lives of the people involved, and take up valuable and precious time and energy that should be put into their fucking wife! (Or husband.) Why do these women at work (who are usually single) get deeply emotionally involved with these men who they KNOW has a wife and children?! Utterly shameless. 