Have Peter and his partner never known anyone who's got married before - a man or a woman? Haven't they noticed that, for the first year at least, they're so preoccupied with the whole unusual idea of being married that they don't have time for anyone except each other? Later they tend to knock around with other married couples rather their old single friends. They've stepped into a new culture and they stop seeing you not because they don't like you, but because they've gone to a foreign land, a land of marriage, and speak a different language.
I know dozens of girlfriends who've wept when their best friends got married. "She's changed; we were so close; we did everything together," they wail. They're bereaved. But at least they understand. They don't start blaming themselves, like Peter and his partner.
Good heavens, they're so sensitive about being gay! Why do they blame their sexual orientation first on what may be a perfectly normal reaction of, say, dislike? Of course, it's true that the husband of their mutual friend may have taken one look at them, recoiled in disgust, and, after they'd gone, said to his wife: "My God, Mary, we're never going to see those friends of Dorothy again as long as I live. Disgusting queers!" But frankly, I think this is such an unlikely scenario that it's far more likely to be something quite else. Maybe he just didn't like them - as people, not as gays. Maybe he felt threatened because they're single men in his wife's past, and their being gay has nothing to do with it. Maybe he feels deeply threatened by all his wife's past, even girlfriends, and wants to wipe the slate clean and start anew. Maybe he's fantastically easy-going, and liked them, but their mutual friend found the situation rather difficult, being with two lots of people she felt so close to, to whom she had perhaps always shown a slightly different persona; perhaps she's the one who decided that it might be best not to meet too often.
It's nothing to do with their being gay - unless, of course, Peter and his partner present their gayness to the outside world before their humanity, which is bound to put anyone's back up. It's as bad as meeting heterosexuals who talk about screwing and bonking and girls' boobs all the time. No, if all heterosexual people were homophobic under the skin, as Peter suspects, and if only 10 per cent of the population is gay, how on earth do they think all those laws would have been passed, making life so much easier for gay people?
By being so paranoid about being gay, I wonder whether, rather than feeling proud to be gay, they're not in fact ashamed? And whether it's Peter and his partner who ought to be put into the dock rather than this woman's husband. It sounds as if they're totally preoccupied with being gay, whereas most of us heterosexuals couldn't give a pin. If they're kind and amusing company, if they're nice human beings - that's all that matters, and it doesn't matter what on earth they get up to in bed.
Of course, they're not going to see as much of their mutual friend - she's married. But I'd continue to ask the couple round to dinner, ask them to parties, exchange Christmas presents, and try to make a new relationship with this pair who, I'm sure, are no different from any other rather selfish married couple in the throes of love.
We've been there, too
So similar was our experience that my (gay) partner of 20 years thought I was its author. We have also had a long and deep friendship with a woman with whom we have shared crises, joys and holidays. She has cut herself off from us since her engagement. We nearly walked out of the wedding reception when the groom pointedly ignored us in the reception queue.
However, I am not convinced that most heterosexuals' gay-friendliness is skin deep, or that our newly remarried friend has suddenly become homophobic. The problem is that her husband is deeply homophobic, particularly as he is a pillar of the church. She has a simple choice: him or us. It is little wonder she has opted for him, probably her last chance for a life partner.
We both feel betrayed, and with no wish to be "tolerated", have withdrawn completely. That is what I suggest your correspondents do.
Confrontation is not the answer
Peter, my experience has always been that confronting (your word) other people with my feelings is a mistake. My anger always gets in the way. You sound so angry, and it appears to be about more than losing a friend. You express it as a blanket condemnation of heterosexuals; this is as unjustified as homophobia itself. Is prejudice what you're so angry about? In which case, your friend's new man could be affected by your anger and is likely to want to keep his distance. By all means, tell your friend how you feel, of your sadness and sense of loss. You could even tell her of your fears - without accusing her partner in any way. But be careful with your angry thoughts. You are in danger of losing her friendship.
Is Peter the prejudiced one?
I don't think that Peter and his partner need to look much further than their own attitudes: "at the end of the day heterosexual people are all homophobic under the skin" for goodness sake! If a heterosexual had made such an unpleasant generalisation about homosexuals Peter would be up in arms about it.
He wrote that he and his partner met their friend's new boyfriend. He should look back at that meeting and ask: did his latent heterophobia come out then?