HaHa! Quite amusing, how well you described a character we all seem to know.
Now, I will maybe make myself unpopular by saying that if that woman has not sniffed beforehand about the habits of the man, she got it the hard way in the midst of spending time with him.

dating for three months. Of course, there could be no sharing of homes during that time because, you know, it was best not to let the kids know about your relationship until it was, you know, serious.

Very interesting, this part in particular. It can't be serious out of the daily lives of the two. It only becomes earnest when kids and household and all the other jazz is part of the relationship. Otherwise I would title it an escape.

edit: I think that's why your headline says "boyfriend", is it so?