Who is this person?

[Day by Day]

Got another email. He wants to see the kids tomorrow for two hours. Then he tells me he'll be out of the country for the week and to "confirm if they will be available".

I'm thinking of replying something along the lines of

Ok. Fine.

I know his LL is words of affirmation but he's been a real jerk lately and doesn't deserve any. So, do I give it anyway or not? My C had told me to "kill him with kindness". I'm getting confused with DB and other advice.