Angry Customer: "*BLEEP* you!"
Cashier: "*BLEEP* you back!"
Angry Customer: "*BLEEP* you harder!"
Cashier: "*BLEEP* you sideways!"
Angry Customer: "*BLEEP* you upside down!"
Cashier: "*BLEEP* you with a whip!"
Angry Customer: "*BLEEP* you with candle wax!"
Cashier: "*BLEEP* you when you are falling down from 10,000 meters in the sky!"
Angry Customer: "*BLEEP* you cause I'd have a parachute!"
Cashier: "*BLEEP* you, because your parachute failed! So *BLEEP* you!"
Angry Customer: "*BLEEP* you! I have a secondary *BLEEP*ing parachute. And when I pull it open, it pulls my primary parachute open!"
Legends have it, the two are still cursing at each other to this day...