I appreciate the responses. I did have a talk with her Sunday morning. It had some friction to it but we talked it out. She initially told me she wasn’t going to let me cause problems or drive a wedge between her brother-in-law and I. That kind of shocked me as that wasn’t my intentions at all. She did agree awhile back that she understood how I felt about showing her brother-in-law her boobs and that she wouldn’t do something like that again and she reminded me about that as well.
Here’s a fast-forward to Sunday:
Her twin sister went out of town for the weekend to visit girlfriends leaving her husband and two kids at home. Sunday morning as my girlfriend and I are laying in bed just talking, he texts her and asks if she’d watch his two girls for a few hours while he goes looking for snowmobiles. She agreed and he dropped them off.
He never comes back for them. His wife (my GF’s twin) comes over and picks them up 6-7 hours later. I had left for a bit to return home to get a few things done before going back over to her place and she had texted me the aforementioned. She said it was disappointing because she had planned on taking her son to the movie. She then added “…but <her son> enjoyed seeing and playing with his cousins so it’s ok.”
This is something he does to her often and she never says anything about it.
Another event is one evening not long after she had her breast implant surgery, her brother-in-law was out at a bar on Wednesday night. Her twin sister needed some help moving furniture. Instead of staying home or coming home to help his wife, her brother-in-law called my girlfriend asking her to go help her twin sister move furniture. When my girlfriend reminded him that she had just had surgery and couldn’t lift anything, he tried to talk her into it saying that it wasn’t heavy furniture, etc. She was annoyed telling me this story. She immediately tried to defend him though when she say that my reaction was one of annoyance towards him as well.
Are you certain this isn’t a boundaries issue? Is this her being a people-pleaser and not wanting to say no to family? Will this “level-out” down the road the longer she and I date?
She is an incredible person with some outstanding qualities. I just don’t know that I could continue to deal with this if she and I ended up married, etc.

