Spoilers for the Abbott Elementary and It’s Always Sunny in Philadelphia crossover are ahead! If you haven’t watched the first half of this event yet, you can stream the Abbott episode with a Hulu subscription.

The Abbott Elementary & It's Always Sunny In Philadelphia crossover had hilarious character interactions, but it hid callbacks in its witty writing.

The anticipation for Abbott Elementary and It’s Always Sunny crossover episode has been building up among the fans of both shows for months, and Part 1 of it is finally here. Aired as Season 4 Episode 9 of the ABC series,

The highly anticipated crossover episode of “Abbott Elementary” and “It’s Always Sunny in Philadelphia” blends the raunchy, NSFW style of the FX show with the witty, family-friendly romp.

As of Jan. 9, the episode is available to stream on Hulu. The second crossover is expected to be an episode of "It's Always Sunny in Philadelphia," which has aired on FXX since 2013.

Here's some background and inside jokes to help fill in some of the gaps for viewers who don't watch both Philly-based shows.

The two sitcoms could hardly be more tonally different, but this week’s crossover episode of “Abbott” was relatively seamless.

A live TV streaming service that includes ABC in its channel lineup will do the trick. Hulu Plus Live TV and YouTube TV are among the options -- both start at $83 per month -- and you can stream the Abbott Elementary episode with Sling Blue if you're in a select city.

"Abbott Elementary" star Janelle James is schooling us on that "It's Always Sunny" crossover and unwinding with the help of "rich people" wellness.

Producers Justin Halpern and Patrick Schumacker break down the epic 'Abbott Elementary' and 'It's Always Sunny in Philadelphia' crossover episode