Oh boy...those "I only married him because I was pregnant" situations are horrible. No man wants to be in that position....ever....it's as insulting as having someone deny you the right to be the father of your children! Deep down, he probably knew she didn't want him which is a tremendously painful notion for a father because you realize "I was good enough to sleep with but not good enough to be with..."
First of all, marriage because of pregnancy is a tough situation for BOTH men and women because there are two questions they EACH are going to ask themselves:
Man: Would I being marrying her if she wasn't pregnant? Would she be marrying me if she wasn't pregnant?
Woman: Would I being marrying him if I wasn't pregnant? Would he be marrying him if I wasn't pregnant?
Second, it might surprise you to learn that 1) Women have sex with men they would never introduce to their family and friends and 2) Men have feelings too.
Third, you are NOT a "single mom". A "single mom" is someone like my little sister who is a widow.
And lastly, if you're so "moral and ethical" about Moms and Dads being together, how can you in all "good conscience" be getting a divorce?