All the while he is calm, cool and collected; not a self conscious smile or giggle in sight. He explained that he had picked the letter "k", which had a picture of a king on it, and she had picked the letter "q", which had a picture of a queen on it. Through this Anushka had decided that they should get married because, of course, kings and queens are married. (Apparently the picking was random, so this is a pretty funny outcome.)
Later, he and Dadam were discussing the upcoming nuptials. Isaac posited that if she were going to be a teacher she would be Mrs. D. Dadam said something about women usually taking the man's last name, so she would be Mrs. W. And Isaac responded, "Or, I could be Mr. D."