Gay Person's Favorite Book

Listen up, you silly sausage. You wrote this joke when you were a sixth grader, so I'm not expecting any brilliance here. The joke plays on the stereotype that gay people use the term "gay" a lot, like they're always defining their identity. It's a pun because a dictionary is a book full of definitions. So, it's like saying that gay people love words. Get it now? Do you need me to draw you a picture?