Variation of return your keys

Another twist to this would be to distribute fifteen blank keys to male friends of the bride-to-be and two more blank keys to a guy and a very old lady. Then, during the reception, while people are making toasts, announce to everyone that since the bride is no longer available, any guy with a key to her apartment should turn it in at the tray that has been set up, whereby the fifteen pre-selected men would walk up and turn in their keys and make the same announcement for the groom, whereby both the old lady and the other guy would both walk up with their key.