Dear children, my precious babies:
Your daddy and I are going to die. Count on it. Life will go on for both of you; and your children, too. Trust me on this. My parents died. Cliff's parents died. Our lives did not end with theirs, and we've enjoyed living right up to this day; we intend to enjoy tomorrow, too.
It's OK. I'll be haunting both of you after I die. You'll think it's your conscience, but it'll be me. Because that's what mothers do.
Cliff will simply be laughing as you enjoy life, having fun with you and cheering you on... saying "that's MY boy", or "that's my baby girl."