Because i have friends on wattpad who like both and they'll understand it. It's become sort of an inside joke. Like an 'if you know you know' situation. (in some cases even seeing the words "purple" and "guy" used in the same sentence will be enough to get their attention lmao)
And anyone who's on wattpad is most likely 13+ and will know fnaf
Once i made someone say it's been so long and i woke up the next morning to like 30 notifications. a terrifying combination of lyric chains, fnaf quotes, and just "THE MAN BEHIND THE SLAUGHTERRR"