turtle16 I understand, but if god understands all, he will understand you putting your children first here. If you are both looking to buy separately, then it may be a good idea to nip it in the bud now. How old is your youngest DD?
I only ask because having dad around may confuse her if hes suddenly not there when you move IYSWIM. Then her behaviour might be affected. I do wonder as well how much his abuse affected you, that your prepared to take him back this easily. Also if your ex won't allow the children to be near him unless extended family are there, then again you will have to ask yourself why. Are there elements to the abuse that your not aware of? Such as did it happen more than you are aware ect?
I understand hes done that and I appreciate it. But part of understanding you've done wrong is accepting the other party may not want to know, and to take responsibility for that. He will need to keep on at this with actions rather than words, but ultimately accept they amy not want anything to do with him. If they do it will be down to time and them seeing he has changed. He should also be doing this anyway, and doing it from outside their home to prove he has their best interests at heart. But be prepared for the long haul in this, and that it may not happen.
I think this man has got in your head and distroyed a lot of your confidence and seeing what is acceptable and what isnt, and the best thing to do now is work on getting him out of your head, and doing that means any contact you have is about your DD and nothing more. Explain that your still trying to work through things that's have happened yourself and would appreciate it if he could give you space to do so. Explain that while you are unsure about things, it's not fair to your DD that he keeps coming over. That he did what he did, it's great he accepts it and is working on it? but you think it would be more beneficial to your older children as well if he could give you all space to work through things.
His reaction to this will be telling.
If he is really sorry he will accept this, and do whatever it takes to make you all comfortable for however long. If he makes the right noises but backtracks and puts pressure on you, you know he doesnt understand nor care about the full ramifications of what he has done.
Give it a year, see how his actions match his words as yours pend that time healing yourself and focusing on your children, especially your son as it sounds like he needs his mum to put him first and do whatever it takes to repair the damage to your relationship
. Maybe look at the freedom programme to help. Doing these things will go in your favour for DS as he will see his mum doing everything she can to protect them, and to ensure it doesnt happen again.