C.L.
I am working on the same problem. My daughter does not want to be around her Dady. She is clingy in general, but with him, I think she looks at him as someone who is taking her away from Mommy. I've realized probably the same thing you've realized, that they d better when I'm not around. I have to actually leave the house, because as long as I'm in another room, she knows it. She really likes talking walks with him and exploring the outdoors. I think part of it is that he doesn't know how to keep her stimulated enough, so when they go out and explore new things, it's better for them both. Hope it helps.