Second Banana

This term comes from burlesque—that is, strip shows. It refers to the MALE comedians who were always part of the show, usually as presenters and commentators. The first banana was the principal comedian, and the second banana was his sidekick. They called themselves "bananas" because they were always around beautiful naked women, and therefore tended to fill their pants with "bananas"—i.e., erections!!!

Joey was the funniest second banana Bob ever had.