Bing's character is a terrible father!
Bing told Joan before they got married that he would be a terrible husband and he sure was. But I found him totally unlikeable when he just ran out on his daughter and basically didn't see her for three years. Even if he and Mary got the divorce, you'd think he would make an effort to have some sort of relationship with his child (who he called "the baby" even when she's now a little girl).
Even at the end, Mary takes him back when he's made no effort to redeem himself as a husband or father.