I don't believe your sister really hates your husband. I think it's more she just got into a habit of talking him down to you. Yes you contributed to the negativity by confiding in her about relationship problems. I think this started off innocently on your part. It might seem like a normal way to converse with a sister. But she's not the right kind of sister to do that with.

Only tell her little unimportant things, like he annoys you by leaving the toilet seat up, or something stupid like that. You know now not to confide the deeper things. Not to her and not to Mom either because they are a tag team and they feed off of each other. They may honestly not know how else to hold a conversation with you. Getting all invasive into your business is how they feel close to you. Each of them needs to focus on their own lives. When you have a significant other - a partner - that person becomes closer to you than anyone else. That's how it's supposed to be. But they feel displaced. They want nobody to be closer to you than them. So I don't think it's about hating him. More that they fear losing you.

What they think of him is their business and not something you need to worry about. What you need to require is that they be polite and not treat him, or talk about him, disrespectfully. I have a brother-in-law whom I don't particularly care for. But I keep that to myself and I accept that my sister and her husband are a "package deal" - take one and you get the other. She expects us all to be reasonably civil and courteous to each other, regardless of what we may think deep down. She has a right to expect that . . . and she does expect that. Her first loyalty is to him, which is as it should be. She expects him to be hospitable to her family, and he is. I think he's glad when we leave, and that's okay too.