I'm sorry, I didn't mean that - of course that's not appropriate - I meant that I would not have wanted to have sex with him, because I would have felt angry and let down. I wouldn't have been wanting to punish him, I genuinely would have felt that at the moment there was a barrier there. I would have been hurt, let down and would not have felt close enough to him to want that.
I was trying to illustrate the point that I think one of the very relevant things here is that you clearly just don't feel like that - your 'default', if you like, is to not get properly angry, even when there is good cause. That's great in many ways - I bet you are a very fair, very level-headed person. But I think in a situation like this - where it's your own DH letting you down - that character trait isn't actually doing you any favours. And I feel quite angry on your behalf about your DH, because I feel - consciously or not - that he seems to take advantage of that.
Think about it. This situation shouldn't have arisen, because a normally 'bolshy' (can't think of a better word) person wouldn't have allowed the discussion on beds to become your problem (the pregnant partner). But it did. It's as if your DH at some level is thinking 'well lightsandshapes is so laid back, she'll probably give in anyway and I won't have to step up and say something to bro.' You didn't, though. So, he saw you were in a bit of a tizz about it, and what did he do? Nothing. Just sat tight, as if waiting for you to give in. Oh sorry, he 'tried'. But no, you don't try in a situation like this - what does 'try' mean? How can you misunderstand 'You aren't having my wife's bed?'
He didn't sort it out before the visit. Then when the visit happened and BIL upset you, he didn't sort that either. Quite the contrary, presumably he was one of the chirpy breakfast crew (maybe a lightly muted chirp, y'know, just to show he was on YOUR side reaaaallly) while you had puffy eyes.
Do you know what, that is DISGRACEFUL. I can only imagine what my DH would have to say if his brother reduced me, while pregnant, to tears.
So, I am wondering why there is this dynamic, and I am thinking that your DH is actualy quite a large coward.
And I am seeing how you are actually reacting to this, how you actually feel, and the message coming over loud and clear is that no matter what happens you aren't ready to really lay any blame at your DH's door. And I think the two are connected - as I said, it is easier for him to upset you, because you will find a way to be ok with him about it even if you are upset with the situation. Much harder an option for him to stand up to BIL.
I hope that comes over as of use and not attacking in any way - I think you are in a very difficult situation and I hope I've been of some help - I really hope this doesn't come across as aggressive or unhelpful - I do apologise if that's how I've made you feel!!