I just so dearly want her little world to be safe, secure and happy.
Given the circumstances, that comment... well there are no words. Few words, maybe. Perverse? Ironic? Utterly shameless? I don't know.
So your DD. She is utterly precious, irreplaceable, you would jump in front of a bus for her. Yes?
Well, to your H, her dad, she is all that because she fits the picture, and if she didn't, she'd be disposable, forgettable, yesterday's trash.
Your DD's world isn't 'safe, secure and happy', and it never will be, no matter how much you play pretend with the setup you have now. Because her dad is a grotesque parody of a dad, a man who can bear to cuddle, tickle, be proud of his little angel when he has another child, another DD, who he is able to discard like rubbish. How would you feel if that were your baby?! Could you sleep at night? Could you look at your DD without wondering whether her sister looked like her, talked like her, laughed like her?
Grotesque really is the word.
Look, I can kind of understand - or at least, before you had your own child - wanting it to be like this, wanting it perfect, wanting it to be your perfect nuclear family. But it isn't, there is another family member out there, and when your DD grows bigger, she is going to look at her dad and KNOW that when he beams with pride at her, that it doesn't come from that primal love a parent has for their child, because he doesn't know what that is. She's going to think instead, yes, you love me and I'm your precious DD because I fitted the picture. You - both of you, you will both be tarred with this - might well not feel the real impact of this kind of destruction of the heart of a family until she has her own children - oh god, she'll judge him then.
Safe, happy and secure is achievable. But not this way. Contact his ex. Make it honest. Not perfect (that's never the case anyway, really) but honest. Otherwise, it's all built on sand.