I will write more later. Pretty busy at the moment.

Give yourself 24 hours at least before talking to him. Damage done, now you need to remedy - and you need the be calm.

Talk to kids. Yeah this is not a great topic. Sure glad she came to you with this.

Breathe. It is ok to be really mad. But breathe and deal with H when you are calmer.

Feelings are fleeting.
Be better, not bitter.
Love the person, forgive the sin.