You say she is your SIL because you are with her brother. You didn't say you are married to her brother. Unless you are actually married to her brother she is not your SIL.

So you have to be married with a piece of paper to have family? Thats honestly not the point here... should I say my sons aunt? My baby daddy sister? I say SIL, what is the difference? I live with her brother, I have a family with her brother.

Inlaws come with marriage. I would just say she is my boybriend or fiance or SO Sister. That way you can forget the SIL thing that bothers you so much. She is just your SO sister.

Okay... no matter what I call her its not going to be enough to change the situation... I'm still stuck with her and the issues are still there. I'm LMAO @ SOS! hahaha

I think a lot of us are saying the same things. You just have to take from it what suits you.

You now have mutual friends. You have to decide if you can share those friends. If not, then it's up to you to decide if you can continue those friendships. It's understandable that you would have conflicted feelings. But if you are the one that is having issues with that then the ball is in your court. I don't think that's an easy spot to be in, but if it's you that has a problem with it than it's you that has to be able to fix it or be willing to walk away.

Yes, it's a crappy spot to be in. I hope you can find peace with this.

You are stuck with her, you're absolutely right. So do you want to be stuck with her and resent everything she does, or do you want to be stuck with her and tolerate her in a good-natured, indulgent kind of way? Hint: the former is WAY tougher on you than the latter.

One thing that really leapt out at me in your response: you say that you need these friends more than she does. How do you know that about her? It's assuming a lot to think that you can "claim" these friends because you need to use them more than she does. Maybe she also needs good friends for reasons that have nothing to do with you. Besides, friends aren't really there to be used like toilets or toothbrushes, so it's not like you and she can't share.

It also surprised me to see how much you seemed to need to unload on your friends about SIL and the rest of the family. If you're feeling this much constant pressure to vent about family matters, you might want to expand your circle of friends anyway to reduce the burden that they bear from hearing it constantly. That's a tough thing to ask other people to do, and sometimes they need a break from it no matter how much they love having you as a friend.

If you can manage it, try to accept the olive branch she offers you. Whatever happened in the past between you and her is history. Let it go. You have a child now and that woman is your kid's aunt, your guy's sister. If you're close enough to call her sister-in-law, you are close enough to WORK on this relationship the way you would any vital family relationship.

It may not work and you and she may just be very different people who don't get along, but...well, again, I'm going to be very honest here and say that people who simply don't get along usually have no trouble just avoiding one another--they don't get jealous or possessive over friendships, decline invitations, and harbor resentments.

Do you really just dislike her or are you still hurt or angry at something she'd done in the past? If that's the case, try to find a way to put that hurt away. Talk to her, meditate, seek advice from a therapist or religious figure (if you're so inclined), but acknowledge that at some point, YOU are the one who must deal with it--not just for your sake, but for the sake of your child who deserves an aunt and your BF who deserves to maintain a good relationship with his sister.

Um, you haven't talked to her about the problems you two have? Maybe that's something you should change. She could have a totally different perspective on this, and she can't read your mind. It's possible that she's trying to steal your friends. It's also possible, like DixC Chix said, that she's trying to extend an olive branch. Maybe she just liked these people and wanted to reconnect. It's hard to tell if you don't talk to her about it. Unspoken rules are hard to follow. When my sister and I were little, we shared a room. There was an "invisible line" marking which side was whose. The thing about unspoken rules and invisible lines is that people have different ideas about the boundaries, and some people don't know those rules or lines are even there.

If you can't talk to her about this, then the best advice I can give is for you to not take your resentment out on your friends. Friends can't be stolen (unless they're kidnapped!), but friends can shift allegiances. If you stop being the person they have fun with and turn into someone who stops hanging out with them because she's going to be there and you spend time badmouthing a mutual acquaintance, it sucks the fun out of being friends. I don't know what your SO's sister has done to you or what her relationship with your friends was like in school, but perhaps you could figure out a way to up your tolerance?

Maybe you can talk to your friends next time you're in the group and she's not around. You can even tell them part of the truth: you trust them and value being able to share your feelings with them, but you don't feel comfortable being open with your SO's sister listening in. Your SO's sister might not understand that it's only venting, and even if she did understand, you don't want to put her in an awkward position. Perhaps you feel like she's interfering with a group where you feel it's safe to share and to be yourself. I don't see why you can't tell that to your friends. It tells them your side without making the other person a villain. Just don't start complaining about her after you tell them that.

I don't think this situation is about which one of you "wins".

I think bargoo's referring to the "in law" part of "sister-in-law".

What did she do that made you dislike her so much?

You are making this situation what it is, and any sadness you are feeling are because of your own actions. If you ask your friends to choose, and they choose her then you have no one to blame but yourself. You don't have to be friends with your SIL to keep your friends. You also don't have to make those friends your ONLY friends. Find new girlfriends that you can spill to about your SIL. The love you have your friends should be more powerful and important and MEANINGFUL to you than the hate you have for your SIL.

I would ready myself for any possible fallout if this girl is hanging out with your SIL. Your complaining to her about the family, but can you trust her to be quiet and not tell your SIL about what you've said in the past?
If you can, than maybe ask that you hang out with her when SIL isn't able to go.

I don't think you can control who other adults are and aren't friends with.I have been on both sides of a situation I preferred not to be around someone and when someone preferred me not to hang around with someone. With the former situation, I simply met those other friends at other times. With the latter situation, I ended up spending time with that person anyway because honestly, I don't feel that anybody should tell me who I should and shouldn't like. I don't think you know that you need friends more than she. You guys were both friends with these people. How does that make you more entitled? In any case, if this goes on, the friends will sense the tension, especially if she goes on about you to them like you do about her. That really puts them at an awkward situation. If they're friends with her, they might not even want to hear bad things from you about her. Why not find new friends that you can talk to about it, or perhaps even consider counseling since it bothers you so much and counselors are as non biased as they can be. It's helped me in the past.

Here's the problem: If your SIL doesn't care that she's friends with you, but you demand that your friend chooses, then you are going to lose. I don't care what beef people have between each other, that's not my problem. Unless it was something so drastic as that person being "the other woman" (obviously not in your case), physical assault, etc. then really, why should your friend "choose"?

If you're the one with the issue then you're the one who needs to let go. I suspect, from reading this entire thread, that you are making your situation much worse than it needs to be.

My MIL (or my baby's daddy's mom, LOL, because I am not married either!) drives me mad. But she isn't going anywhere. She is family, a family *I CHOSE*, when I got with my baby daddy (LOL sorry, I had to). So I deal with it maturely and let it be. Only when she insulted my parenting style did I respectfully state to not speak about me in that manner. Other than that, I shrug everything else off - there's no need.

It seems like whatever happened between the two of you bothers you a lot. Do you think your SIL is aware of this?

I used to be one of those people who lashed out when I was younger but I'd like to think I'm more drama-free nowadays. I'd like to think I've changed since then. Has your SIL given you any reason the most recent interactions to have ulterior motives? You are with her brother so I would think she would want peace and acceptance. If she is really that intolerable, then your friend Dee will see it too and make her own judgement about being friends with her.

I tend to like to see other people prove my initial opinions of them and for their true colors to show instead of making me look like the bad guy/show insecurity. Let them hang out with who they want.

People are not bought and sold and they can choose their own friends and who they want to associate with.

Playing devil's advocate...

Are they your real friends or the people you bash your baby daddy's family too? If they are your real friends, you can overcome the fact that they mingle with your sil, you will have a relationship that is bigger than venting, it may even be the bridge that fills the gap and brings some closure to whatever it is between you and her. It cant be easy for your man and his parents that you hate his sister. My son and daughter are very different, yet when it comes down to it, they love each other no matter what.

You can vent here...or find a select few that you trust...just remember what you put in print can be forwarded to another and may come back to haunt you.
dont do things in haste that you may regret later. It seems that if you cut them off and they stay friends with her, it will only add fuel to the fire of hate that you cant seem to let go of.