To cut a very long story very very short, my recently departed father had two daughters with a married woman in the 60s. The story my mother was told was that the husband was not fertile and they made their own arrangements with my father. One daughter was born in 1964, around the time my parents met. The other is about a year younger than me, and a few months older than my next oldest sister. My mother did not know about this one.
Thing is, apparently my father went on holiday with the woman and the two daughters for a very long time, until they were in their teens in fact. Christ only knows how he managed it but he did. My mother must be mad have the patience of a saint. It wasn't a question of them being entirely someone else's children. My father took an interest in their upbringing. He broke ties with the family when they allowed the oldest daughter to pose for soft porn photos in her mid-teens. Otherwise he probably saw them as often as he saw us.
One of my sisters now wants to find our half-sisters to tell them our father has died. Another thinks we shouldn't in case they don't know. I kind of err on the side of letting sleeping dogs lie. Two of our siblings have no opinion on the matter.
WWYD?