My partner of 8 years is going away with his sister this year, the third year in a row. For context, they're incredibly close and since he moved out of the family home 3 years ago, have made going away together for a few days a yearly thing. She is about 14 years older, single, living at home and very successful.
Other than family, she doesn't have many friends or anyone to travel with. She organises and pays for everything on their trips so all he has to do is turn up.
I thought by now it wouldn't irritate me as much as did the first time, but it does. Am I in the wrong for feeling annoyed and somewhat, left out by this? I don't come from a family where I am close with my sibling so have never understood their relationship. She is a lot older and always seen him as a baby, and still does. They're in contact every day as he goes to her a lot for work issues/help.
These trips are usually pretty extravagant and I can't help but feel that as my partner we should be experiencing these things together. But I don't know if that's just selfish of me to say.
It's also irritating as I'm in the process of sorting a trip out for the 2 of us with no help from s/o. Then without warning, he puts in our joint diary he is going away with his sister. Which happened to be the exact dates I was also looking at.
He doesn't see the problem and thinks I'm unreasonable for being annoyed and should just be happy for her and him (as he would be for me). However, I feel as though sometimes her doing this is trying to 1 up me. My partner would never see it this way and it might just be my insecurities playing into it. But it sometimes makes me feel like he doesn't even need me in his life, the way he is treated by the women in his life (mums & sisters). Beyond these trips, they do a lot for him, buy him a lot of things etc.
Ultimately, I find the situation odd. Am I overacting?