'It's Always Sunny...' has plenty of recurring jokes that have gone on to have a life outside of the show.

Granted, nobody's created Fight Milk just yet, nor has Bird Law become a real thing, but it's been all but proven that Dennis was based on Ted Bundy. In fact, another deep-cut joke from 'It's Always Sunny' has now become a reality. In the fifth season episode, 'The World Series Defence', Mac reveals that he's written a love letter to Phillies' second baseman Chase Utley.

The letter, in which Mac professed his admiration for him and desire to play catch with him, became a recurring joke in the series, and cropped up a couple of times during the series' run. Here's that letter. Oh shit, there's stickers.

In fact, Chase Utley even responded to the letter a few years after the episode aired. Last night, however, saw that dream become a reality.

On his retirement game with the Phillies, Chase Utley walked out into the stadium with Rob McElhenney and played a quick game of catch with him. The scene above actually played just before the moment took place.

Take a look.

You can actually see the look of genuine happiness on McElhenney's face when he catches, probably because he really was / is a fan of Utley. Credit where it's due to the Phillies for actually going along with this, not to mention Utley himself for taking part.