I know that I am probably being unreasonable and I give this too much thought but I still feel such disappointment with my sister for something she did 20 years ago.
She is 2 years younger than me (52 and 50) and she (imo) has always been my parents golden child even though she has given them nothing but hassle since a small child and I have always been the people pleaser and 'good girl'. I am sure she displays some narcissistic behaviours at times.
I could write a story about my sister's colourful past but she has been settled with her partner for around 20 years now but sometimes the way she talks about other people and her opinion on the way they conduct their lives you would think she has lived like a saint, she really hasn't.
Her relationship with her partner started off as an affair on his part. My sister was single and they worked together. They started a secret affair and after a short while he left home to be with my sister. The thing is that he wasn't simply married, he had 4 very young children and another on the way. Admittedly, the ex-wife is not a nice person and has been a terrible mother (another one with a very colourful past and even her now grown dc dislike her) but my sister has always used that as justification for happily setting up a home with a married father of 5. His youngest was born after he left. Dsis and bil have always had the dc over several times a month and the kids have a fairly good relationship with her and do adore their dad (he is actually a very nice guy despite what he done) but it really does grate when my sister is running them or their mother down. All the dc (now in their 20's) have issues which I am sure stems from the fall out of the affair but my sister can never see that and always blames the mother for all the wrong doings within the family.
I have never shared my view on this as it is not for my to have an open opinion on it. Neither has my dh (we have been together since we were 16 so he has been part of all this from the beginning), we obviously have an opinion and it's one of great disappointment but we appear to have been the only ones feeling this. My parents (now elderly and mum has dementia) have always been onboard from the very beginning and welcomed my bil with open arms, even buying him a car when he left home with absolutely nothing.
It goes without saying that it is not worth bringing this up all these year on but sometimes when my sister and I are having a heated discussion which we unfortunately have a bit more regularly now as we both help our parents out a lot as dad doesn't cope well with mum's dementia and it is putting us all under a lot of stress so nerves are often frayed, I will feel like letting it all out.
I just hope that I never say anything as I will regret it but how do I let this go, it's 20 years later ffs but I look at his kids and see a trail of devastation which my sister seems oblivious to and feel that 5 damaged young lives could have been avoided had he simply left his wife and waited a while before setting up home with my sister.