Boyfriend (23M) thinks I’m (23F) overreacting to the fact that his family didn’t invite me on their vacation but they invited his brother’s (25M) girlfriend (25F)?

*tl;dr: my boyfriend’s parents didn’t invite me on their vacation but they invited his brothers girlfriend. They also never make any effort to include me in anything yet they always include her. We’ve been dating twice as long as they have and I’m feeling left out but my boyfriend thinks it’s not a big deal. It’s making me feel more and more insecure and I just want to be included. What do I do?
So I’ve always had a feeling my boyfriends parents don’t like me, I don’t know why they wouldn’t, I haven’t done anything wrong, they just don’t. For example, we’ve been dating for 2.5, almost 3 years and I’ve only met his parents once. They’ve had multiple opportunities to see me when they come to visit my boyfriend but they never invite me on the outings they have. They’ve also gone on several family trips together while we’ve been together and I’ve never been invited on any, and my boyfriend used to blame it on the fact that we hadn’t been together that long, when they invited his brothers girlfriend on their trips after they had been dating less than 6 months. Ever since then she’s always accompanied them on their trips, gone to their family weddings, spent the holidays with them, and I’ve never even been invited.
It’s just painfully obvious to me that they’re going above and beyond to include her, and not doing even nearly the same for me. In fact it feels like they’re going out of their way to leave me out on purpose. Whenever I bring it up to my boyfriend he says he always tries to ask his parents if I can come with them to these things too, and they always make an excuse as to why I can’t. He also says that I’m overthinking it, that of course they like me, “they just don’t know†me.
My problem is, they’ve made zero effort to get to know me, yet they always reach out to his brothers girlfriend. They invited her over for dinner the second they started dating and they’ve basically been inseparable with her since. With me, my boyfriend had to beg them to meet me just once and they seemed to like me but they’ve never made any effort to want to get to know me since. As I’ve said before I’ve literally met them once in almost 3 years of dating.
What do I do? It’s making me feel extremely insecure and left out, especially since this is my third holiday season with my boyfriend and I’ve yet to spend any holidays with him because of his family. I just feel so unwanted and like they’ll never like me. It’s hard to see them having so much fun with her and know that they’ve made an effort to purposely leave me out but include her. It’s making me feel so insecure.
**edit: my parents always go out of their way to include my boyfriend and make him feel welcome so that’s not a reason as to why his parents might not be including me.
**second edit: we’re all white and nonreligious so it can’t be anything like that. They also have always tended to favor the brother over my boyfriend unconsciously over the years.


Source.