But you have said it too often, Mr. Benedict!" said Mrs. Perusal in an imperious tone that was quite out of character. "And if you continue in this vein, I'm afraid we'll be compelled to cut our visit short. Surely there are other establishments that would host an entire group of guests - indefinitely and without reward - and not feel obliged to apologize for it!

The Mysterious Benedict Society and the Prisoner's Dilemma