Her story about him being a secret sperm donor doesn’t ring true to me. What clinic would just accept anyone’s sperm in fertility treatment? Have you talk to the clinic that did fertility treatment?

They conceived a baby normal way having an affair but now telling you bogus stories about sperm donation. Sperm donation is a lie unless you sued the clinic and got it proved that they used whoever’s sperm unbeknownst to you. She put you on a birth certificate before even telling you that you aren’t a biological father. I really don’t get it, why are you still married?