Communication - Where did I go wrong?

I'm not new to the board but if someone would go to this thread, I posted there. Didn't know I had to sign in on each new thread, however, I need some feedback from my post.
The post I responded to had something to do with a husband and wife and her computer and she heard something in her husband's tone that possibly wasn't there.
I didn't know how to post a thread until I checked around and found this page. So....someone, please read my rather long post and reply back. Thank you.
My situation has to do with something my partner said about my sister who's going through dire marital issues. My partner thinks my sister will never find another man (her 3rd. marriage) who would "put up" with her emotions and I don't know how spouse (hers) has managed to put up with her this long. They've almost been married three years this August. He told me, "I'm sorry, but that's the way I feel." That really hurt and I felt numb, shocked and angry. It's like he can't accept her level of emotional, mental and psychological problems. When my sister first met her spouse, he accepted her for who she was. My partner feels it's one thing to say that, another when you're actually living with the person.
I don't know what to say anymore or how to feel.
I told my partner if my sister sends him an e-mail to both of us, okay but if he gets one from my BIL, I don't need to know about it. If I get an e-mail from her, I'm not going to let my partner know.

Welcome to PC, Here is your original post. You can find them under "my profile" until you unsubscribe.

Sorry, I don't have a reply but DO have a problem and it hurts me....a lot!
My sister is about to come and stay with my partner & I for a few days, perhaps more, I don't know. She wants to think about whether she wants to separate from her spouse. She has multiple emotional disorders as well as physical health problems.
Monday night while discussing her and my BIL with my partner, he basically said that he's surprised his BIL has stuck it out as long as he has with my sister (this yr will be their 3rd. yr of marriage). He also added that no man would be able to handle her moods. Recently my partner and my BIL have bonded and next week, both men are going to a city an hour's drive south. My partner will be asking, maybe point blank, what's going on with their marriage.
My partner told me Monday night, "I'm sorry, but that's the way I feel."
She's staying with us and my partner has a problem with hygiene, he HATES long hairs, especially hers. Plus, she'll be bringing her dog and cat and the dog, she sheds and the thought of her hair on the carpet, is mortifying to him.
My partner and I have hashed this out, quite a bit over the past several weeks.
The major problem with my BIL is that he won't open up emotionally and considers any questions as being "interrogated" so, needless to say, counselling hasn't worked because he doesn't see their marriage as having any problems. When they first met, he felt that sharing was a novelty and at some point, that abruptly stopped. He's not big on telling how he feels and that's become a major problem between them. He feels their marraige is okay as long as there are no "deep" conversations. I've tried explaining to my partner that in a marriage, it takes communication from both partners for a marriage to work.
My sister is a hyper sensitive individual and is easily hurt. BIL can be decent, loving, somewhat sensitive and caring but he can turn 360 degrees and blame her questions about them, on her. She hasn't been eating much if anything due to emotional stress and sleeps a lot if he gets verbally nasty, criticisms, putdowns. He's done it while my partner and I have visited, done it while visiting us.
I like him, did feel fond of him but HATE his behaviour.
I felt incredibly numb and my stomach very tense Monday night and was very quiet. Shocked is probably closer to what I felt. I told him if he gets an e-mail from both of them, that's okay cause she sends me the same e-mail but I also added that if he gets an e-mail from my BIL, I don't need to know about it. I added that if I get an e-mail regarding her stay here and what happens should she decide to live here while struggling to get back on her feet, I wouldn't send it to him. He's unfortunately, like his late mother, quite judgmental.

I'm sorry this isn't a response to those needing help re: the title communication - where did I go wrong? That is my question too.
Thanks if anyone's reading this. I really need to know how anyone feels about what was said by my partner and yes, he has a right to his opinion but he's so insensitive to what emotional issues are and how they affect people. I have many of the same but not to the degree she does. He told me, again, Monday, something like, well you don't act that way.

What is it that has you so upset? His comments about your sister? Just because he loves you doesn't mean he's going to love your whole family. I would hope that he is pleasant, kind and civil to them, but he really doesn't have to like them.

Neither you nor your partner can do anything to help your sister get her marriage straightened out, it's something she and her husband have to do. By all means give her a shoulder to lean on, but otherwise stay out of it. You are getting her side, your partner is getting his side, and the truth is probably somewhere in the middle. Right now it sounds like you are bringing her problems into your own relationship and that doesn't help anything.

I have to say I really don't get on with hubbys sister and he knows it and stays out of it, we just don't talk about it anymore he knows how I feel.

I am not married to her I am married to her brother so we are polite to each other and thats it.

I think I could agree with AAAA. We all are individual and thus have individual opinions on things. A good relationship is one whereby we could give the other the space to be themselves, have their own opinion.

You need to be careful not to let this complicate your relationship with your partner. It would be wise to learn not to let other opinion affect you.

Reach is sooo correct. In the last month or so I have learned a lot about myself, and one thing I learned...I would put my opinons on my wife, and only mine were right! Yeah, whatever...sooo not true. She's an individual and has her own ways of doing things and her own opinions, as will your partner, accept that, and if you can't, maybe you should rethink your relationship.

(((imo)))) i think it can get very complicated having 2 families living together. you and your hubby have a relationship and now other ppl's dynamics are brought in. i think what aaaaa said and reach are good suggestions for you. you will need to keep you family intact and not let others impact your relationshp. i know u care for your sister. you can be there for her but remember that it's important to protect your own relationship with hubby regardless of his opinion on the matter.