I wouldn't go back to him until he is strong enough to parent his child and teach her how to treat adults. The problem isn't so much the BM but your fiance.

Keep your house, raise your child in a happy environment and get on with your life. If you want to wait for him, then fine. But quite frankly, this man has two other people ruling his life right now and he's not in a place to have a real relationship.

You were wise to move back home.

I can see both sides to some degree. How old is this girl? You can not change the past but he must have know she had issues with you. I think he should have done the therapy before you moved in. As I see it, you both have sent a VERY STRONG message to his daughter...she had a meltdown or whatever you want to call it...then you moved out....She clearly knows...SHE HAS THE POWER. What she did is what they call...emotional blackmail.

Wish you all the best...she seems to be a drama queen. With a controlling BM,I do not see therapy will make much difference. You can not fight crazy.

If you stay, be prepared for BM to continue assaults as much as possible. You have to grow thick skin. He shouldn't have to pick a side with you and daughter. BM shouldn't tell her to do that, but again, the assault is never fair. Your fiance should let his daughters know what he expects out of them and you as well. You are not there to replace their mother. You are not there for their crap either.

I would suggest he bring some one into the home for counseling. I am a big big believer that when it comes to getting kids help, sitting in an office is not all that. Bring the care into the house to work with her and dad. When you get a dog and you hire a trainer the trainer does not sit in the room alone with the dog, the trainer, trains YOU or in this case Dad, to deal with the issues and set the boundaries that just will not be tolerate. I feel bad for you. But it sounds like you did the right thing. He needs to work with someone that will be stern. She can be angry all she wants and she can talk about it, but she will not set the rules in the household and she will not act in inapropriate ways. Good luck to you all.

Apart from the just moving in and then straight out I almost could have written this.

My OH has 2 kids - sd14 and ss11. SD is a nightmare. Her mother hates me and has poisoned them both about me, my very existence is a problem apparently.

OH and I were high school sweethearts, we found each other again not long after we both ended unhappy marriages, and had such high hopes and dreams. We love each other, but it's not enough to counter the skid drama. He is torn between them and me and unfortunately for me, they win.

The skids arrive here for the weekend visits and march straight through the room I am sitting in like I do not exist. They go straight upstairs, and stay there until tea is ready. Then back up they go. If OH wants to interact with them he has to go where they are. Usually by Saturday night they have thawed a little (after spending all day playing and going out ALONE with him) and will play with my dd's 8 & 11 and come down to watch a movie. Sunday, rinse and repeat Saturday, they stay upstairs and if he wants to hang with them off they all go. I am a non-person in my own home. They generally refuse to acknowledge my presence, speak to me, rarely will be in the same room as me.

It's driving me batty too, as my OH can see no problem with it.

I feel for you OP, but I think you moving out is the best option. Move out, move on. Date him I guess, and see whether he can get his brat under control - she doesn't have to like you but respect and civility should be mandatory (wish MY man would get this)

I would never leave a relationship or a home over a POS kid manipulated by a toxic PASing X.

Rather I would let the little shit rot in her room. Good riddance if she never leaves it when she is visiting.

Fact:

It is your home. The BM skank whore cheated and left. It is no longer her home.

BM is PASing this kid and this keen daddy to give her the facts relative to the entire situation. The facts will help the kid arm and protect herself from manipulation by the toxic BM.

Abdicating the home and relationship to this little girl just empowers this toxic manipulative crap.

Your BF needs to man up and parent instead of being a coward non-parent.

IMHO of course.

Good luck.

While I can understand getting up and leaving, because in reality, who needs that shit?!?! I have to agree that you should have NEVER given that little bitch & her c*nt of a mom the satisfaction. I remember WAYYYYY back in the beginning of my relationship with DH, when BM would try every God given tactic to get me to leave him. As much as I wanted to leave because the drama was just so overwhelming, the ONE thing (besides my DH) that kept me put was the fact that I refused to give that bitch the satisfaction of running me off.
She eventually gave up. It took her almost 14 years to give up, but eventually, she lost steam when she realized I wasn't going anywhere. Now, we rarely even hear from her. DH gets a text MAYBE once or twice a month or so. LOVE IT!

You might suggest to your fiancé to look into AL-non for his daughter on top of the therapy. With an alcoholic mother (who is also bitter and toxic after the divorce)this young pre-teen is dealing with a lot. Her mom is a hateful spewing drunk, her father is moving on and she's feeling very threatened by this new lady is Dad's life. It's not you personally. She'd react this way to any woman . Don't let the child intimidate you. She's a lost little girl caught up in all the drama of her parents divorce and her mother's dysfunction.

I'm personally not a believer in moving into a well established house that the divorced couple shared and was also a longtime home to any stepchildren. IMO couples need the freedom of a fresh start. One where neither of the new couple can be set up as 'the outsider' or living in a home with too many ghost of past linger. Even if for now both fiancé and you keep your current houses but rent a new place together. One where this child would still have a bedroom but one she wouldn't feel quite so comfortable declaring 'hers' and taking up root in waging a battle.

Also, your 20yr old daughter might be able to help get through to this young pre-teen. DD is old enough to be a role model as somebody who has already 'been there, done that' on divorced families and learning to let go of what the children in these situations can not turn back the clock and change.

She had a fit and got her way. You moved out.

ALL of it pivots on the biodad IMHO. If the biodad is a spineless weenie and refuses to see his kids manipulating him as well as the PASing that's being done with the BM, but instead blames everything on the SM insisting she kiss arse as well, then it's not SM's job to straighten that mess out.

If the biodad stands behind SM and makes an attempt to parent his children, well then that MAY be worth staying for.