Family Relations

My father died before I, Fiona was 8 and I can't remember him very much at all. But we were okay it seemed we had everything we needed over the years. The only man in our lives was uncle David 48 younger brother of my mother Jane 51 and he is very smart completed his university courses before the age of 20. Got a very good job never married and we lived with him, Jane looked after his house and he looked after us financially. It didn't strike me as strange, that I had 3 younger siblings by the time I was 16. All born after my father's death, even as I got older it didn't occur to me to asked who their father was. I hadn't seen my mother date in all years since my father died. She got pregnant and I had another sibling, finally while searching my birth certificate. I came across my siblings birth certificates, listing David as their father. I was shocked at first, but then thought my mother had a romance got pregnant and the man cleared off. So David's name was put on the birth certificates. I remember thinking how unluckily Jane was 3 assholes leaving her pregnant. But she never dated and the man I saw her with was David. Then last year I had an early finish at my university, I would normally go shopping with classmates. But instead went straight home instead, my sibling were still in school. I got home and went inside and without calling out I went looking for jane and found her in her bed with David fucking her. I didn't say anything and was unseen by them both and now I knew. Uncle was really my siblings father and my stepfather, it took 17 years for me to realize uncle David was fucking my mother his sister Jane.