Special deal for straight couples only — friends went anyway

Our group was composed of 2 straight couples and 2 gay couples, which makes 8 people. We had to wait about 3 hours for an 'escape' game and some of us were hungry, so naturally we went exploring the mall for restaurants. We found a cool-looking Japanese place.Upon approaching it, before entering, the hostess told us there was a special deal for couples where the gentleman paid X and the lady paid Y. It was an all-you-can-eat buffet situation."But what about gay couples?" "Well, we can't actually give them this deal. For girls we might make an exception and they'd get the deal price; but for male-male couples I'm afraid we cannot offer the same discount. I see there are four males not accompanied by females in your group, so I'm sorry but there's nothing I can do."They went in — two straight couples and the other gay couple. Both men later paid full price. My boyfriend and I followed them to the table, but we got up and left before they even started eating. We were shocked at the blatant homophobia and the lack of support on our friends' part.About half an hour into the time we had to wait, my boyfriend texted the group saying the restaurant was homophobic and everybody should get the same deal. No one replied. It was on WhatsApp so he was able to tell when they had all read it. Hours went by and not a word. I was so devastated. These people are my friends, I introduced my boyfriend to them because we're in a band he's not a part of. The other gay man, who's been in the group for only a few months, only came out to us and introduced his boyfriend to the gang because he saw that I was gay and that made him feel safer.A couple minutes before the time we were told to show up, he came find us. He quickly told us that they didn't think it was a homophobia case — but rather a sexist case on the grounds that women were perceived to eat less than men — before the others got within earshot. I'm not arguing this: I think it's both. I'm the person who eats the least in that group, and there are two women in it, meaning our very group is proof that this stereotype is nonsensical.Going further than anecdotal evidence, the main reasons I think defending the restaurant is bullshit are:Say the food consumption volume gap is true, for the sake of argument — no one's making the owner offer any sort of deal to begin with, which means he or she made a decision to be unfair / homophobic / misogynistic rather than to give every couple the same treatment and arguably risk losing money;I'm not sure whether someone suggested it or if the hostess herself said it, but at some point I heard that men could pretend they're boyfriends for the discount if they allowed gay couples to have it — as if women can't pretend they're lesbians or straight people in male-female pairs can't pretend they're couples (seriously, what a pathetic argument right there); and finally,Gay people have this annoying habit of bending and stretching any reasonable argument in an attempt at appeasing straight people in power. We call it something like doing tricks for a cookie around here.We played the escape game and went home quickly afterwards. Still not a word about it all. Only exchanged pics after the end — we won.I'm still mad at them all, perhaps more than I am at the restaurant because I don't expect any empathy or support from straight strangers — as I do from my close friends. It really broke my trust, which sucks because I find it particularly difficult to begin trusting somebody. I'm feeling... I don't know, I guess hurt.I'd like your thoughts on this, please, amazing Reddit people. ❤