Matt Groening said this quote

“ Where do babies come from? Don't bother asking adults. They lie like pigs. However, diligent independent research and hours of playground consultation have yielded fruitful, if tentative, results. There are several theories. Near as we can figure out, it has something to do with acting ridiculous in the dark. We believe it is similar to dogs when they act peculiar and ride each other. This is called making love. Careful study of popular song lyrics, advertising catch-lines, TV sitcoms, movies, and T-Shirt inscriptions offers us significant clues as to its nature. Apparently it makes grown-ups insipid and insane. Some graffiti was once observed that said sex is good. All available evidence, however, points to the contrary. ”