I suspect you left your last thread because of the 'pile-on' that ensued and I suspect that this is going to go the same way.
I'd like to gently point out that the 'pile-on' was instead the frantic response of posters desperately telling you that your situation is incredibly wrong and very likely dangerous. It no doubt felt like an attack so you stopped posting.
You must know in your heart that this man shouldn't be near you or your DD's and your DSD. They will be learning very quickly from you that these standards are so acceptable for them. And should you choose to let him stay as they grow up, they will see more, understand more and learn more of this. They will then, quite likely, run away from you and your home at the first given opportunity and are nearly guaranteed to end up with problem partners. Your babies will suffer the same.
Is this what you want?
You feel that, somehow you are responsible for the well-being of this man? You are not.
Did lockdown prevent you from telling him to leave? You sounded scared to tell him to leave in your first thread - I can actually understand why. Did you imagine that he'd make a scene, shout, cry etc? Trash the place?
Your life is a very unhappy picture OP. YOU can change this. There is nothing appealing about this man - that in itself is a good enough reason to end the relationship. Reading the other thread however is very, very alarming.
Are Social Services involved at all with DSD? OP, you must surely realise that if they knew your circumstances, they'd question your perceived loyalty to him and then question the safety of the DC in the house?
Can you talk to the DSD's mum? You need to alert her. Nothing you tell her will be a surprise to her, but frankly, this isn't of importance. Tell her what's happened and to be prepared to change her DSD's contact situation.
Be prepared to text him when he's out of your home, that you're ending your relationship. He can collect his stuff (which you will bag up) at an agreed time.
Do you have any brothers or cousins that can support you? Any friends that can be around when he collects his things?
Locksmith - change locks.
If you can't do any of these things then you really need to ask yourself why. Why are you putting the needs of this man above the safety of your little girl and his little girl?
Please OP. Both your threads make me incredibly uneasy - you must take back control here. You have much to lose.