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.

The long-running TV comedy series, “It’s Always Sunny in Philadelphia,” returns Wednesday, July 9 at 9 p.m. ET on FXX.

You would think a show like It's Always Sunny in Philadelphia would lose steam after 17 seasons. Instead, it's better than ever.