i am the holder of the AP and say my FIL wants to pay for the meal (certainly not going to argue with him) can they still apply the discount?
Charge it to your room and have your FIL pay it at the resort desk a day or so before you check out.
If it's paid in cash, nobody will question.
That is exactly how we did it.Charge it to your room and have your FIL pay it at the resort desk a day or so before you check out.