Watch Your Mouth by Daniel Handler

Watch Your Mouth is a novel by the American writer Daniel Handler. It tells the story of the protagonist Joseph's lust-filled college summer he spent with his Jewish girlfriend, Cynthia Glass, in her hometown of Pittsburgh, Pennsylvania. Handler has described it as an "opera in book form".

When Joseph goes to stay with his girlfriend Cynthia's family for the summer, he plans running the crafts shack at camp by day, and romping in Cyn's bed by night. As the summer grows hotter and stickier, life in the Glass house begins to shatter in all kinds of irresistibly gruesome ways that only the fiendishly funny imagination of the author of "The Basic Eight" could conjure up.