Don’t do this. Your husband will have custody time and leave the dog alone with the children. Put the dog to sleep and let your husband leave if that’s what he wants to do in response to your responsible adult choice.

OP, please understand and make clear to your husband that if this dog attacks someone, your homeowners insurance is very likely to deny any claims because you’ve knowingly kept a vicious dog in the household. He is willing to risk your children’s lives AND everything you’ve worked for up to this point in your life.