If I take a moment to speculate about this guy I wonder if he feels insecure and like she's always just waiting for him to leave so she "can" go see her kids. But there's a really easy solution to that, which is to respect her bond with them and appreciate her company when she is around! And go do something with the kids now and again!

He's a dick. I wanna believe she will have a come to Jesus talk with him of some kind, but I have to be honest, when people write to advice columns asking what to do in response to obviously dickish behavior, I think they're just starting to grasp the problems in their lives and hard boundary-setting will take a while yet.