AceShowbiz - The highly-anticipated crossover between "Abbott Elementary" and "It's Always Sunny in Philadelphia" is getting real. On Thursday, October 17, "It's Always Sunny in Philadelphia" star and creator Rob McElhenney delighted fans as he shared on Instagram the first look at the upcoming crossover.

In the picture, cast members of the two fan-favorite comedy shows can be seen uniting on the "Abbott Elementary" set. "It's Always Sunny in Philadelphia" stars, including Rob, Kaitlin Olson, Danny DeVito, Glenn Howerton and Charlie Day posed alongside "Abbott Elementary" cast members Janelle James, Lisa Ann Walter, Sheryl Lee Ralph, Chris Perfetti, Tyler James Williams and creator Quinta Brunson.

While "Abbott Elementary" cast all looked beaming in the group snap, "It's Always Sunny in Philadelphia" stars appeared to be in character as they were frowning and making some faces. "School's out y'all," so Rob wrote in the caption.

Fans showed excitement in the comments section. "How were the gang even allowed near the school let alone inside," one jokingly asked. "I just know frank shouldn't be within 15 feet of a school," another added.

"There's definitely drinking in that teacher's lounge," one fan commented, while someone joked, "Is.....is Charlie going to learn to read and write?" A fan was thrilled to "see Charlie and Mr. Johnson queen out."

Quinta also caught wind of Rob's post and left a comment. "Rob I'ma get you," the Golden Globe-winning star playfully wrote.

While plot details of the crossover are still unknown, Quinta previously talked about the crossover during her appearance on "Jimmy Kimmel Live!". "I was very inspired by watching a lot of shows over the pandemic," she explained. "I was binging 'Family Matters' and 'Full House' and stuff like that, and I was shocked at how shocked I was when Steve Urkel showed up on the 'Full House' set. I was screaming at my TV."

She then revealed that she connected with Rob after social media comparisons of their shows, which are both set in the City of Brotherly Love. "Something came up online, and he was like, 'Someone said this seems like a 'Sunny' episode, this seems like an 'Abbott' episode,' " Quinta added. "And then we kind of connected over that. And then we really connected in person, and I just get along with him and his team so well, that we felt like we could actually do this."