This is going to be a long one. I was separated in 2018. I have since remarried and have successfully co-parented with my two children's Dad since then. Including mixed family says, my ex and his girlfriend coming to my wedding, family roast dinners etc. For the last year things have been difficult as my ex's new partner is physically and mentally abusing him in front of my children or with them in the house. My 9 year old has told me he has had dreams of her stabbing him to death. I've tried to work with my ex to protect my kids and in August he agreed for now they would stay with me whilst he broke up with her and sold his house. Since then they have got back together and broken up more times than I have fingers. A few weeks ago he took the kids out for a drink and told them if they didn't go to his house he wouldn't financially provide for them or see them again leaving my 11 year old hysterical but adamant she was too scared to go to his house and my 9 year old not wanting to go either. He then sent messages telling my 11 year old she would feel the consequences and love bombed my 9 year old who he thought was going to start going back there. We have no court ordered custody agreement just what we previously decided between ourselves to do so social services got involved and told me to keep my children with me and only offer for him to see them with me there which he has refused multiple times. Social services have now said he has told them he is taking legal action so as the children are classed as safe with me that they will be pausing their investigation until a judge tells them to investigate. Both children are currently refusing to speak to him on the phone however my 9 year old is sending him messages about football but not answering his calls. I've tried to persuade the children to see him but ultimately they don't want to because he gave them ultimatums and told them their feelings were not important. They are genuinely scared of this woman and what she is capable of. Is keeping them with me the best thing to do?