Simons wrote this with Tearce, her co-writer and producer. She told Digital Spy
about the song: "We wrote it in 2008 when I was working on my album. It's about a guy I know who's an a--hole. Some people would call him a "player" or a "Casanova", but those words have kind of become compliments. There's no way anyone could say 'Silly Boy' is a compliment. No guy wants to be called a silly boy."
Digital Spy asked Simons if the guy knows the song is about him. She replied: "I think he knows now because I've been calling him 'Silly Boy' for a while. He's down in my phone as 'Silly Boy' too."