Why do men do this!?

Short and sweet this is my second pregnancy. And i got knocked up with yey another with a man who up and abandons and leaves his child because the baby is not a girl. It makes no sense to me. Sure we both hoped we woukd have a girl but I guess im just meant to be a boy mom but both exes were more than dissapointed with the fact that i was not pregnant with a girl and thats not my fault!