Ok, I'm going to say I don't think the problem is your DD. She is reacting like I think any little girl would. Her whole world has just changed. As you said, she used to have you all to herself!

I'm not sure how your DP's relationship with your kids has been developing in the past so I'm just going on this thread here. But I don't think him taking a big role in disciplie with your kids straight up is a good idea. Think about it from their point of view. They move in with a new man and suddenly he "is calling her on everything", is angry at her for (IMO) normal silly kid stuff. I think you should continue to be the person who discipline the kids for a while and then slowly get him more involved. I really think he needs to back off in this adjustment period.

I'm not really understanding the set-up here either. You keep saying she is constantly wanting to you while you are down spending time with DP?? Can't she come down with you if she wants you? I would think she would definitely feel put out if while she's home you're spending time with DP and she's not allowed to come down with you?? Am I missing something? Sorry, I might not have read something in a previous thread.

I think her behaviour is pretty normal. She definitely needs to know that lying etc is not ok and that there are consequences. But she also needs a lot of love right now and is obviously having a hard time adjusting. Go gently. It is a big change! And if you change your whole discipline strategy at this time she is likely to associate it with you moving in with DP and resent him for it

I'm sorry that this is causing problems in your relationship but I really don't think it should be. Your DP needs to cut her some slack. He shouldn't be angry at her and not wanting to be around her. I get that he is annoyed that she scratched his chair but if he wants to live with you and the kids he has to understand that **** happens and you need to deal with it and move on quickly otherwise everyone will be miserable.

it's a tough adjustment but you will work it out.