If he took them off and wiped them, then put them back on her it'd probably work okay. But yeah, someone trying to wipe your lenses off while you're wearing them just isn't going to work at all. And his fantasy's worthless, since the fog's on the inside of the lens.Wiping someone's breath-fogged-over glasses like that while they are still wearing them is like trying to get a rock out of someone's shoe by tightening the laces.
You're accomplishing nothing at best, but probably hurting them with the pressure even if you're trying to be gentle.
I had no idea I had a visceral glasses related trigger buried deep inside me.