With another woman. At the time we had a 2 year old and I was pregnant with our twins. I had not finished college yet, I put that on hold when I got pregnant with the twins. When he came to me and told me, he truly was sorry and even though I hated him for it, I considered my options. I was about to have 3 kids under 3, I had at least 2 more years to finish college and I did still love him.
The woman was 12 weeks pregnant when I found out (DH had cut things off with her around the time she got pregnant and didn't speak to her again till she called him and told him she was pregnant the day he told me phone records confirmed this.)
I told DH that I was not going to deal with his bastard, it would never be welcome in my home or around me or my children. If he was to pay child support, he would have to get a second job to do that because the money for his mistake wouldn't be coming out of our family's budget. I told him those were the conditions and if he would accept them, we could work it out and stay together. He agreed. He, with me there, called her and told her that if she wants child support, she can go to court for it but he is not leaving his family for her (as she wanted him to do) and his 3 children with me have to come first. She told him that she would never contact him again and hasn't.
Very few people know about it, only my sister and my best friend. For all we know, she may have had an abortion. I know that some people will think I was wrong for basically taking a father from a child but the way I see it, its mother did that when she chose to have sex and get pregnant by a married man. The other option was to turn my children's world upside down and I was not willing to do that if I could help it.
That's my confession, exactly 5 people know about it (my sister, my best friend, DH, me and the whore). Our children don't know and will never know, we have a good relationship now and have 4 children and one more on the way. BTW I finished college.