Brief back story: my parents divorced after a long marriage and my father has since remarried.
Around 12 years ago, he started socialising with a couple. The woman was around my age and was in a relationship with a much older man. When they split up, she continued her friendship with my father.
Around 10 years ago she asked my father to give her away at her wedding. I'm not sure if he did but he did attend the wedding. The groom's mother arranged a lunch to meet my father prior to the wedding.
All these years later my father is still very close to her. He has helped her professionally and text and speak frequently.
My mother, brother and I have each independently concluded that my father is actually her father too. My brother isn't bothered about finding out. I think my mother would like to know as this woman is around the same age as me.
I'm not sure if I need to know or not. Part of me does want to know. She has children around the same age as mine and my children would love more cousins. I also think it is very sad if my father has kept their relationship a secret. Sad for her, I mean. And probably for him too.
Should I confront him and ask him for the truth? I am truly undecided.