Most people have been addressing his unfair attitudes about the potential threesome, which is good. But I want to give you my perspective as someone who also tends to have a broody personality. I get mad easily and, if I let it, it takes awhile for it to blow over. While I'm angry, I want to be left alone.

But the thing is, except in extreme circumstances (and I'm talking major betrayal, potentially relationship-ending stuff that anyone would need some time to get their head around, like finding out your partner had gambled away your savings or something), it's not okay to just ice out your partner like that. Taking some time to cool down so you can discuss things somewhat rationally, sure, that's fine. It's pretty normal to need a few hours, maybe even a night, to cool down. But you still need to communicate, and you can't leave it hanging indefinitely, and you can't use that time to punish your partner.

Your boyfriend is using the silent treatment to punish you, whether consciously or not. That other couple backed out, so now you're bending over backwards to placate him, plus he's making you feel insecure in your relationship which makes you more likely to bend over backwards to keep him happy in the future. This isn't healthy.

I wouldn't be reassessing whether I was okay with a threesome if I were you. I'd be reassessing whether my relationship was really as good as I thought it was.