Antlers, it's a tough sitch with no easy solution. Your ex actually said she cannot handle daughter and she is not around to supervise her. I have a 14 yr old boy, and he does what I say, he whines, complains, talks back and tells me how mean I am, but no matter, he does what I say. Your daughter needs to come to your house, it's not her choice, she is a minor, she has no say in the matter, don't ask her. When you described what she was doing I thought she'd be was 17 or more, she is still underage and you are responsible for her, so no more asking, she does what you say and the rules stick and if that 20something guy better stay off, she is a minor.
As for your son, who's paying the cell phone? 50-70 texts?? that is insane. After 4 lengthy texts I just pick up the phone. He gets nothing until he improves his behavior, if he texts you more than 5 times he looses his phone, period. A cell phone is a privilege. I have taken all sorts of things away from my son for talking back to me (that's the worst he's done). For weeks he's gone without internet, ipod, xbox. Right now he's 1 month grounded with no Netflix for messing with me for not giving me the controller of the wii when I asked him to and being disrespectful.
They'll call you mean and others, that's fine, that is your job. The dean of my school would say "if your kids don't call you mean you are not doing your job".
A great book that has helped with my teen, who is a good kid but morphing into a teen is "for parents only" by shaunti feldhahn. Above all, pray earnestly day and night over them.
Be not afraid...I will repay you for the years the locusts have eaten Joel2
30something 2kids survivor of S, MLC, A, D I have peace in my heart, at last.