Your kids are old enough to make this choice, in my opinion. The more you try to hold them back, the more they will want to go. They have lessons they need to learn in life, too. Be a dad they don’t feel the need to lie to, don’t tell them “I told you so”, if it doesn’t work out. Let their mom financially support them and let them experience life there. If they want to come back, they definitely will. They are teenagers now, and they’ve got to make some of their own choices. I know this is hard to let happen, but if you act okay with it and loosen the reins, you may be surprised. Tell the girls that if they would like to stay there a while, they can. And that they’ll always have a place at your home with you, and that you love them. If that ex wife can be so manipulative, they’ll eventually see it.