I have good reason to believe a close family member doesn't have the Dad they think they do. They have a sibling that they think is their full sibling.
It is an open secret between their Mum and the Mum's siblings, although it isn't spoken about.
The man who brought this person up as their own doesn't think he is the Dad and took the split with the Mum very badly. He was planning on doing a DNA test surreptitiously but decided against it.
This family has a lot of secrets that just about everyone seems to know anyway but no one talks about.
I am torn about somehow telling this person that their father isn't who they think it is but, for purely selfish reasons, I am reluctant to do so because it would tear the family apart and I would be made out to the bad one.
AIBU to keep schtum?