It’s Always Sunny In Philadelphia season 12 episode 10 served as the season finale and ended on the cliffhanger of Dennis potentially leaving the show. It’s Always Sunny In Philadelphia is a dark sitcom centering on the miserable lives of the Paddy’s Pub gang, consisting of Dee, her twin brother Dennis, Charlie, Mac and Frank. The show has run for an incredible fourteen seasons and counting, with its popularity slowly building over time.
It’s Always Sunny In Philadelphia is the polar opposite of more colorful, feel-good sitcoms such as Friends, which is part of why it’s been running since 2005. It’s set to continue its reign as one of the longest-running live-action sitcoms too, as it was renewed for another four seasons in 2020, though it’s unknown when the next series will debut.
It’s Always Sunny In Philadelphia season 12 opened with the episode “The Gang Turns Black,” which was a bizarre ode to musical The Wiz and episode 2 “The Gang Goes To A Water Park” featured cameos from Game Of Thrones showrunners David Benioff and D. B. Weiss. It’s Always Sunny In Philadelphia season 12 episode 10 “Dennis’ Double Life” opens with the bombshell that Dennis has a son named Brian Jr thanks to a one night stand with a woman named Mandy (Christine Woods), and this season finale sees him try to wriggle out of his responsibilities.
Charlie also seemingly does the impossible after twelve seasons of stalking It’s Alway Sunny’s Waitress (Mary Elizabeth Ellis), and after a horrid presentation where he convinces her that her life will be slightly better if they had a baby, they sleep together. Afterward, when she starts seriously discussing future plans, so Charlie freaks out and runs away and even accuses her of stalking him. When he has no other good alternatives, Dennis decides to pretend he’s in a relationship with Mac in the hope Mandy will just leave, but still wants him to be part of Brian Jr’s life.
It’s Always Sunny In Philadelphia season 12 episode 10 ends with a ridiculous staged scene where Dennis tries to convince Mandy he’s actually a secret agent but after a mistimed bullet squib and gunshot effect – combined with his less than stellar performance as a dying man – Mandy gets the picture. She hands Brian Jr to Dennis to stay goodbye, with the latter looking uncharacteristically emotional. The final scene sees the gang celebrating with their signature dance moves at the pub, aside from Dennis. He abruptly stands up and decides to head to North Dakota to be with Mandy and their son, to the understandable shock of the gang. After some awkward dramatic pauses, he leaves.
It’s Always Sunny In Philadelphia season 12 episode 10 ended on this cliffhanger because Glenn Howerton had landed the lead role on sitcom A.P. Bio. It was initially unclear if Howerton would be able to appear on both shows, and the production played into the mystery of if he’d be back at all. It wasn’t until It’s Always Sunny In Philadelphia season 13 premiered that it was clear Howerton was still a main cast member, though Dennis was absent for a few episodes of that season. His return is essentially handwaved away, which is very much in keeping with the show’s tone.
