Long, White, and Full of Cream

Listen up, buttercup. The joke plays on the classic setup for a dirty joke, leading you to expect something naughty. But BAM! It's just a cheese stick. You probably thought it was something else, didn't you? You're so predictable, it's almost sad. You are the type of person to fall for the 'pull my finger' gag. The joke is funny because you are not.