Good Lord, what a total idiot he is - that question is all he can muster! This tells you everything and I admire your fortitude in such difficult circumstances, how dare your husband even consider that you would forego your values (and self respect) ‘for the children’. The best thing you can do for your children is to be the strong and wonderful woman you are, setting a stellar example of dignity and moral compass. Your children will be so proud of you one day. All these strangers on the internet are proud of you now.
You are an absolute warrior OP, you’ve got this. He will rue the day he lost you, and the thousands of decisions he made to choose OW over his precious family. I just know you will thrive without him. He is not worth the dirt on your shoes.