I agree with @JazbayGrapes.
And if she does end up spending more time with him - you need to keep your head held high, keep calm and keep up with the communication when she's with her dad - even if she doesn't respond to texts or pick up calls etc. You keep it light and cheery.
I don't bombard my kids but send cheery texts, offers to go for lunch, coffee, shopping trips etc (Have to admit it's costing me a fortune). I've tried to take a different view, I've spent years being the responsible one, now I can get to be the more 'fun' parent.
I'm not surprised that my kids want to spend more time with their dad - he's hardly been there for them for the last decade or so. So for him to finally show an interest must be lovely for them.
However, you mentioned that he is controlling. He may still be trying to control you through her. Do not give him the satisfaction of letting him know how devastated you are and don't let her know you feel hurt, if she wants/needs to come back, she needs to know the door is always open. And she may not do that if she thinks that she's hurt you.
Has his maintenance payment gone up recently? My ExH only moved closer after he got an amazing new job and his CMS payment went up by nearly 50%. Then suddenly he was no longer asking me for a spreadsheet of how his CMS payment was spent, he was actually back in the parenting room.
He sometimes tells me my kids must hate me because they no longer live with me, but I know that they love me and that he's just being a hateful tw@t.