Note: The following story contains spoilers from "Abbott Elementary" Season 4, Episode 9. When "Abbott Elementary" creator Quinta Brunson mentioned the idea of a crossover episode with "It's Always Sunny in Philadelphia" -- fueled from a conversation with Rob McElhenney during Disney's upfronts -- showrunners Patrick Schumacker and Justin Halpern agreed it would be fun,

Charlie Kelly can finally read this sentence. Probably. In Wednesday night’s Abbott Elementary and It’s Always Sunny in Philadelphia crossover episode, Charlie Day‘s lovable idiot from the long-running FX comedy had some help in getting hooked on phonics,

The star of the FX series also admits he was initially hesitant about the crossover concept as 'It's Always Sunny in Philadelphia' heads into its 17th season.