Impossible situation

[Travelfairy]

Posting here for traffic.

Not really an AIBU, more what would you do in this impossible situation?

Deceased Dad had a love child, who is now an adult. I became aware of this accidentally about 14 years ago. She reached out via letter shortly after my Dad's death asking to open contact (no previous contact at all, just knew she existed and a first name). Letter went to Mums house, she did show me but then destroyed the letter.

Mother and sister strongly opposed to any contact whatsoever and its implied I would be a traitor if I made contact...I'm struggling with this but dont want to hurt my Mum any further.

Has anyone been in a similar situation and how the hell did it pan out? Its like the final taboo. No one knows about her, none of my Dad's family, none of my friends. I have no one to talk to about it.

I know someone who was the love child.

I think you all come to your own terms with it. Their sibling wasn't okay with it.

They had a relationship with the parent but it went sour. There was some strange revenge seeking behaviour against someone connected to the half sibling that they got drawn into that I didn't quite understand. I think it was some kind of moral high ground thing.

Psychologically, and I am sorry this is a blunt question, how would you stop yourself not asking in your own head 'did he like me or them more'? That question may not occur to you but this would be a natural human response to meeting someone who you had shared your dad with for the first time.

I find it odd that your mother and sister blame your half sister for anything. The only thing I can think of is if they think she should have cut her dad out of her life for being a cheater - but that doesn't make sense if your mother knew and stayed with him.

My guess would be that your mother may want to pretend that the affair didn't happen, and of course any mention of your dad's other daughter would interfere with this. And your sister may feel the same, or may be going along out of loyalty to your mother. You've heard your mother and sister out; now in your place I think I would weigh all the pros and cons and make up my own mind whether or not to pursue contact. I think for each of the three siblings, wanting contact or not wanting contact can be a perfectly normal and understandable choice, no judgement needed for anyone. I wouldn't assume any ill intentions from your half sister pursuing contact.

My Mother (and sister to a lesser extent) are very much stick your head in the sand people. I try confront problems head on. Whether they acknowledge my half sister or not she still exists and the affair happened whether they choose to try not think about it or not.

I am going to take a couple of weeks to think about it and make a decision. After 4 years she might not want contact now, she might feel very hurt.

@Travelfairy
the part that is utterly unreasonable is your mum focusing her hurt and anger on your dad's child who had zero to do with her own existence. Demanding you don't have contact? Your dmum needs to get a f-ing grip. Seriously.
You absolutely should reach out to your half sister. Why on earth wouldn't you? Loyalty to mum? Anger at dad? Fear she may want inheritance? FFS if the law allows it then give her the share she is entitled to. Even if the law doesn't, do it anyway. She's blood. This may help make amends, too.
Imagine how she grew up? Perhaps longing for her dad; wondering why he didn't want her?
Make amends, build some sort of relationship. Don't wait.