Ah - I missed that. Still, I think it makes sense to 1) answer either "yes, I am seeing someone" or "no, I am not seeing someone but I am free to do so and I probably will start d@ting soon" or 2) not engage at all. Skirting the issue is counterproductive. The soon-to-be-ex cannot expect that the OP will remain single forever and making it clear that she has no intention of doing so and he has no say in her d@ting life now seems prudent.
Turtledove, I think you're assuming that he has no ulterior motive here. I agree, he has no say in her dating
life - so why is he pestering her to find out if she is seeing someone else? I would be VERY hesitant to tell him anything about my life or doings at all. I think he is looking for some sort of ammunition - if nothing else, if she says "Yes, I have a new relationship
," he may try to use this to blacken her name to their social circle - "See, (sob), my love of life has a new lover, and she's rubbing my nose in it
!" (Yes, many confirmed philanderers will do this, just so the other spouse is seen as the "bad guy" in the breakup.) If she's not dating
, he can then tell the mediator that any demands she makes are due to her jealousy, "because I've moved on, and she's still hoping I'll come back to her."
The worst case scenario would be someone who would become violent if his suspicions are confirmed, or be more willing to make an assault on the home if he's sure no man would be there with the ex-wife.
Her life, with or without a new partner, is not his concern any more. Confirming her status as dating
only confirms that he still has an interest in her doings. She needs to cut that string right now.