H has started an affair 2

[mvgfwd2]

You need to act as if H is gone. Move his stuff to the garage. Fire him as the babysitter, he has failed at that repeatedly. He is coming and going at his convenience because you let him. Have a new babysitter in place as the PRIMARY babysitter, not H. If he gets home in time to take care of them, good for him, otherwise he is done as the babysitter.