Only child, resentful of my adopted siblings . . .

Kelly, you are not alone! That headline did grab me - for all the same reasons you posted this. kindred spirits we may be. I am on your side and empathise completely.A bit of background: my parents couldn’t have children (so they thought) and adopted my sister. Then I came along. My whole life I was ‘trained’ to treat my sister as ‘one of our own’. She had been with my parents since she was a newborn, after her 14-year-old mother had a one night stand with some guy whose name she didn’t even know down the local pub and chose to give the baby up for adoption. Her choice - no one else’s. Anyway...Growing up, I never saw my sister as adopted, just as my sister. We looked nothing alike - she had the olive skin I could only dream about, whilst I was fair. I was tall, she was short. She had dark hair, mine was light. Polar opposites, really. In teenagehood, I was always the good girl, she was always the rebel. We were very different people but were still reasonably close. We loved each other as family. When she had kids in her early twenties, I was rapt to be an aunt and never looked at my nieces as anything other than my nieces.That all changed when my ‘sister’ went behind our backs to find her birth family. My whole life, my parents had told my sister that if she ever wanted to find her birth mother they would help her, support her. But she didn’t ask for our help, instead choosing to enlist the help of a pushy new friend she’d made. I’ll never forget the hurt in my parents’ eyes when she sat us down to share her ‘happy news’ (which we thought was going to be another baby, but was in fact that she had found the woman who birthed then abandoned her). In my view, my parents had always treated her more favourably, and they still do now even though she’s in her forties. They continue to make excuses for her and to claim they understand why she has made the decisions she’s made. They might understand, but I don’t.I get it that she would have been curious, trying to join the puzzle pieces that make her who she is. I understand that she wanted to meet this woman and ask her questions. I don’t know if she ever found the answers from the birth mother she was seeking, as she never told us. She also found out that she has biological half-siblings (twins), who now also have their own children. My ‘sister’ has embraced this other ‘family’ and now treats them as her own. She regularly travels 3-4 hours to see them, and far more often than she sees me and my son, whom she claims to love but never sees. We live closer (about half an hour away) and our town is actually on the way to the biological people’s town. On Facebook, she has her biological half-sister listed as her actual sister, the birth mother listed as her actual mother, and they have the same for her. Worst of all, my nieces have them listed under family. None of them have my parents or I listed as family. It’s incredibly hurtful. My youngest niece (now 17) has also in the past told us that ‘you’re not my real aunt/grandmother/grandfather’ etc. My sister keeps in touch with these other people constantly and I am so very, very disappointed in her. I can understand having questions she needed answered, but I don’t understand why she keeps the birth mother and her extended family in her life when they abandoned her as the dirty by-product of a one night stand.To all the people telling you to have empathy for your adopted siblings, they need to consider it from our perspective - the non-adopted child perspective. Our PARENTS decided to adopt. Our PARENTS went in fully aware of what could happen when the apple of their eye decided to find their biological relatives. WE DIDN’T HAVE THAT LUXURY, and are expected to simply, blindly and happily accept the repercussions of having a sibling who is adopted and all the BS that goes with it.I totally resent my ‘sister’. I now use that word with mirth, as no true sister of mine would ever have betrayed our family. If my parents were no longer living I wouldn’t care if I never saw her again. I completely empathise with you, and thank you for posting this as I have searched for a long time to try to find someone who simply gets it - and you do.