Thanks WH.
It's now evening here and D17 has just gone out with friends. But she still doesn't have her phone and I am worried about how I'll know where she goes and what time she'll be home. Normally, she phones me with updates and to ask permission throughout the night.

She tried 3 times to ask stbx to let her have her phone when she got home from school this afternoon. Each time he hung up on her as soon as she got a little agitated - he was taunting her in the way that he used to with me. When he has something we want, he has POWER, and he likes to wield it.

It could be that my improvements in giving up resistance towards him (no more arguing, trying simply to validate his feelings) have left him without a target. So now he's transferring his rage and power struggling onto D17.

It's like 2 teenagers going at each other. But dangerous, too, when what is at stake is her phone - a safety/security device that lets me know where she is.