Silly Billy is essentially Boyfriend from an alternate universe.

In the FNF mod, it was initially believed that the lyrics were directed at the player, but they were actually meant for Girlfriend. The lyrics in question are: "I'll make you say how proud you are of me, so stay awake just long enough to see my way, my way." The backstory is that in his universe, Girlfriend dies to random circumstances, driving him to insanity. His desire for Girlfriend to remain by his side is so strong that he manages to retain a part of her essence. It's unclear how he accomplishes this—perhaps Silly Billy has the power to keep her soul close, or maybe Girlfriend's prolonged presence has enabled her to cling to Boyfriend.

Girlfriend's presence is now also evident in the mod's introduction. When Silly Billy uses the microphone to push Boyfriend away, a red glow can be seen on the microphone, indicating Girlfriend's presence within it. Additionally, a red aura briefly manifests during the lyrics section, symbolizing Girlfriend's lingering spirit attached to Boyfriend.