There are shows that come and go, and then there’s It’s Always Sunny in Philadelphia, a sitcom show that somehow never really disappears. It slips under the radar at times, but it always comes back.

When the narcissistic gang from "It’s Always Sunny in Philadelphia" visited the "Abbott Elementary" school in a crossover episode earlier this year, audiences got to see the two Philly TV universes collide in hilarious ways — all while keeping the episode PG for "Abbott’s" more family-oriented viewers.

In Wednesday's Season 17 premiere episode of "It's Always Sunny in Philadelphia," the "Abbott Elementary" cast gets to cuss — including the "c-word"!