My sitch is differnet in that my D's (17 and 14) live with me 24/7 (H moved 1 hr+ away and he said they should live with me). So I haven't seen any resentment there.
I do give them time together when they are talking etc (if I am home as he visits them there..another story). They do go out some for Dad and D times too.
Part of the room thing is definately that they are teens and if you see him take it personally you could say something that let's him know they do it to you too. "Are they teenagers or what? The way they hide in there rooms sometimes I think I'm being ignored (say it lightly and wink at him or something to show you get it).
My youngest D has the biggest problem with H and while it's a little to lengthy to go into here. When she get's into her "I don't like my Dad, why do I have to visit with him" stuff, I just say he's your Dad and it's important and that's just the way it is.
