Your SO is an ostrich- it is very common for these dads to bury their heads when it comes to their children, leaving their wives/SO to handle these complex feelings and issues as best they can.

You are in a difficult place and I really hope you can work your way through it for your own sake- that happiness you are so desperately seeking will not come without pain in the interim. At the moment you seem to have the best of the three options, which is to live apart but see each other without the entanglements of parenthood. He is pushing for a reconciliation but you need to be careful here and ask yourself if it really is what you want? I suspect it isn't, for the reasons you have given. There is a basic and understandable lack of trust on your behalf- but being with someone you can't trust is never ideal, as you say, the issue rears its head again somewhere down the line. It will happen, and unless you put things in place together for these eventualities, you will both revert back to previous reactions.

Do you leave now? This is tough and a question I asked myself it many times, thinking for a long time it was not an option for me. Now I am having to come to terms to being without a man who could not see (or didn't want to) his own weakness as a parent which impacted on our relationship in a very negative way. I am away from all that now and I am remaking my life. I hope that you take your time with this- and that what you decide to do is the best thing for you. Let us know how you get on.

My opinion is it will not change. She is 14 and it has gone on too long; it is who she is now.

You will have nothing but constant turmoil when she is around and anxiety thinking about when she comes back. I bet you have it now just thinking about the possibility, don't you?

He will start resenting you for "ruining his relationship with his daughter" and you will resent him because he lied when he said the things were going to change and they don't.

I think you have correctly assessed that nothing has changed with SD's behavior or your SO's parenting, and therefore you would be nuts to allow him to move back in.  The first question you have to ask yourself is will you be happy with a "part time" relationship until SD is launched, with the ancillary question - is SD likely to launch at 18?  Based on the parenting she gets from her father, I'd say the answer to the launch question is no, but it could be that the BM is pushing her in that direction.  You did say that BM doesn't tolerate SD treating her boyfriend rudely, so maybe BM also makes her help, do chores, study, etc., and she'll be off to college or independent living at 18.   If you're willing to date him for 4 or more years, and that works for him, that might be a viable solution.  However, if you're looking to get married right away, start a family or have the full time support and companionship of a partner, this probably is not the man for you.  

Let SO come for just a weekend with SD14.  Do not say a word about the promises; just observe if SO carries through with SD14 as he promised.  Observe how she treats you and SO.  If it goes well, you can plan another weekend later and ease into it as time passes.  Give it lots of time, before making anything permanent.   Now is a perfect time to work it out, if possible, without going back to what it was.  If SD14 does not behave and show you respect, ask SO to take her to her grandmother's for the remaining time he has to spend with her.

If at any time it seems to be going back to what it was, tell SO, "we'll stay part time", or if you know you cannot work with it, leave and move forward. 

Good luck and keep us posted.

I know your SO says it will be different but it doesn't sound like it is any different at his parents' house.  Does he think he is going to automatically start having her help around the house when they get to your place.  Also, at her grandparents house with her dad she is the center of attention.  She doesn't feel threatened.  What happens if they move to your house?  I'm thinking she'll again act out, feel threatened by your mere presence and resent you because if she has to start doing chores she'll think it is all your fault.  Have you thought of counseling for you and him - it might help you get your thoughts and priorities straight before you go back into the relationship.  If you do choose to have him come back maybe go to counseling with the daughter and the counseler might be able to help her.  Just my 2 cents. 

Keep doing what you’re doing. Date him if you like him and leave the SD out of it. No, he cannot move back in... and it’s very telling that he hasn’t gotten his own place but instead moved in with his parents.

I still date my ex... 4 years of being with him and we separated/he moved out because of his parenting of utterly unlikeable kids. We broke up for a year and for the last year he’s been coming around 1-2 times a week and whenever he can leave his brats at home or with someone. I am traumatized from living with the entire lot of them. He and I get along great- we’re travel buddies, enjoy similar interests, super comfortable (we dated in high school 20 years ago) etc... but his parenting - oh good lord- guilty, wimpy, inattentive, allows himself to be disrespected, just gross, and I can’t watch it. Does it suck sometimes? Sure. I’d like to have “whole” relationship. But if it’s with him it won’t be for another 10 years until his youngest goes to college. Honestly I can’t even call him my “man” because who could admire a man who gets disrespected by children? Yuck. 

So while I see other guys *sometimes* no one holds a candle to my ex because when it’s jusr us without the kids, everything is great. He now has sole custody of his kids now and they don’t see their mom (she’s in another state and lost custody of her entire brood of CS checks).  No way will I ever willingly invite his broken brats back into my life... and I LOVED, cared and prayed for them. But nope. Gotta protect myself. I hope you do the same.  

Advice- has he taken parenting classes? Gone to therapy? Done anything to prove to you that things will be different? Be real with yourself.

you know what it’s like living with him. He’s not going to change. He says he will... that’s just the stress of living with his parents and lack of having YOU around. He hasn’t learned how to be a parent in 5 months. It’s not easy... especially if he didn’t start at birth like an adult is supposed to! 

Date him girlfriend and get all the benefits of being courted by him... you’re doing the absolute best thing you can do. 

You are dealing with a teenager that’s not your birth child *give_rose*!! I admire you. 

I have had the same issue in the past and patience is a virtue. A sense of humor and a daily massage could help also. 

Sounds like he is parenting out of guilt and what makes him feel better and not what’s best for the child. Disaster will ensue and you see it and he doesn’t. She will become dependent on that kind of pull and push behavior. 

I personally think you have it good right now and until the teenager grows up and moves on then consider something more permanent. 

If you want to have them both back in your home permanently- do it gradually.

I would also ask for her help in doing something fun that you know she would be good at. Like baking, internet issue, creating a gift basket for an event, asking her opinion on travel issues (if you were me which place do you think would be more fun to go?), watch a TV show she watches and ask her about the characters even if she is not watching with you, have a girlie time getting your nails done, things that she may not do with her Mom or Dad so you could connect on a different level. Don’t expect great results at the beginning but slowly enter her realm. Arrange for board game nights with the three of you and let her win sometimes. Tell her something funny that her Dad did and make her laugh. She is just a pawn in this whole arrangement and has no choice in where she stays when her father has her. So you have that choice to be the person who makes her secure in a home where she feels welcome or decide you want your sanity for another couple of years! It’s not easy but I did it and  in the end you feel you gave it your all and hope something good comes out of it.

Oh and put her period date on your calander to be prepared for those couple of days beforehand! Her emotions will be haywire. Also helps if she has access to things needed around that time. 

On the subject of your SO - you cannot change how he behaves with her. It sounds like it’s already established. Parenting classes can help and some places offer them free.