“I want your seat to be closer to my family”
Brings back memories. A guy was sitting in the aisle seat that I had reserved and paid for. He wanted to sit next to his wife in MY seat. Long story, but he threatened the stewardess (I understand that’s illegal), and was given a choice to move /behave, or the Captain would produce handcuffs until the local police removed him.
Set a price. If he doesn’t meet it, the spouse sees how much it is worth to him.