The Mystic Adventures of Dorian

The next morning, Dorian wakes up to the ringing of his phone. On the other end is a dog barking, then a smack and whimpering. After a few moments, a voice comes onto the line. The voice belongs to Meg, owner of a pug.

"Please excuse Sir Kenington's barking. I'm calling about the piano lessons. I saw the ad on the fire hydrant just before my dog relieved his waters on it. I felt bad since my dog ruined your ad, and decided to call."

How does Dorian respond to this?