AITAH for not wanting my sister’s poly side girlfriend at our small family Christmas
My sister is bi and poly and has been with her husband for about 10 years. A few months ago she started officially dating her girlfriend alongside her husband. Her husband also started seeing a new girl.
We had Thanksgiving at my sister’s house with our immediate family, which she invited her girlfriend to. It’s her house so she didn’t really need to ask us, but we were all kind of surprised that she would do that since the relationship is new and unconventional.
Less than a month later, my sister told me her girlfriend has moved into the house my sister owns with her husband. Even though her husband has a girlfriend outside the family, he is not trying to involve her at all to the same extent and I don’t think he has ever even brought her to their house.
Now I’m hosting our small family Christmas at my place, which has always just been my siblings, our mom, and our long term partners (like my sister’s husband and my partner.) It seemed unspoken and understood that it would just be us, but then a few days ago my sister asked if she could invite her new girlfriend. I don’t want to make her upset, but I just want our family there because it’s a small and intimate gathering where we eat dinner and open presents. It just seems wildly out of place for her to involve someone that isn’t her main partner with the family and I don’t know why she doesn’t realize that. I don’t want her to feel attacked for being poly because I don’t care that she has multiple relationships, but I wish she would keep her side relationships separate from family. And even if she wasn’t poly, I don’t think it would be appropriate to bring such a new relationship and someone we’ve met once to our small and intimate family gathering. AITAH for not letting her bring her girlfriend?
Edit: This gathering is not happening on Christmas day, but several days before. Her partner is not alone on Christmas, I’m assuming they will spend it together.
I’m also sorry for referring to her partners as “main” and “side” and I see how this can be offensive. I’m just not ready to accept a new partner on the same level as her husband who I have known for 10 years. Most of my discomfort stems from how fast her relationship is moving and not that she’s poly.
Edit 2: I’m not looking at comments anymore but thank you for giving me many perspectives to think about. I love my sister and this will help me have a conversation with her and understand her better.
