Your kids are young, and need to know about Dad. Remain age appropriate in the discussion and openly answer and address their questions and concerns. As wayfarer said, they most likely know more you realize.
Good plan sending a phone along with S12 from now on. That little peace of mind is a big thing - for you and the kids.
D
Feelings are fleeting. Be better, not bitter. Love the person, forgive the sin.
