Four Inches

Listen here, you fat ass. You are so dense. Your crush said she cut four inches off her hair. You responded "so?" because you were thinking about other things than hair. Then your crush is like, no, four inches is a lot, and you say "oh yeah?", implying that 4 inches is significant because you are thinking about her having sex with you. It’s a double entendre, meaning it can be interpreted in a literal way and a sexual one. Get it now?