I am terrified of my BF's SIL-- what if BF and I get married?
The middle paragraphs kind of turn into a rant, and I apologize. If it's tldr, you can skip to the last paragraph...
Background, BF's living situation: He rents a house with his brother and his brother's wife, SIL, so we all have to see each other on a fairly frequent basis.
In the beginning, SIL and I got along fairly well, but very quickly she became a raging YouCan'tMakeMeSayIt. Towards the end, she stopped talking to me altogether, and even takes great lengths to pretend I'm not in the room-- even if I address her directly. She ignores me, but if BF pays her the same compliment or asks her the same question that I did, she directs her answer only at him. When she's pissed at me for something, she directs her comments at BF ("Can you tell HER that she needs to stop being such a slob?") even if I am sitting right next to him.
As for the slob accusations, that is entirely unfair... while she was pregnant AND moving into the new house AND trying to organize her wedding, I would frequently try to help out by taking out the trash or doing dishes, or sweeping up a bit because I noticed that if I didn't the trash would sit and stink, the dishes would mold, and the floors would be muddy, because every one else was too busy to do anything about it. But all she had to say on the subject was that I was doing it all wrong, and she didn't want me to help any more... and that's when the Slob accusations started, because I'm not ALLOWED to clean up after myself any more.
She'd rage that I'd eat their food, then when I bring over my own drinks or snacks, she'd throw them out unless I hid them in BF's bedroom. Same with shampoos and toilet paper... But when MotherInLaw is over the house, she fakes sweet to me and tries to get chit-chatty.
BF and I have had very serious talks about our relationship, and at one point we were considering getting our own place together. If our relationship leads to marriage, that means I am permanently stuck with this miserable woman as a SIL... For now, when Mom or Dad are around she behaves herself, but I know that won't last long... What am I supposed to do?