It's Always Sunny in Philadelphia: Season 6

Hearing that Carmen (the trans woman he met in "Charlie Has Cancer" and secretly dated in "Mac Is a Serial Killer") has finished her gender-affirming operations and is married to a man, Mac protests against gay marriage, although everyone else thinks he's jealous that Carmen didn't marry him and that he might be gay because he slept with her before her gender-reassignment. Meanwhile, Dennis marries his high-school crush, whom everyone else hates because of her bad breath caused by a dead tooth;

Disillusioned, Dennis decides to divorce his wife; Charlie and Frank decide to split up; Dee discovers that Bill is cheating on his wife with her.

The Gang purchases a boat and disagrees on how to use it: Dennis, Mac, and Dee want a party boat, while Charlie and Frank want a shrimp boat.

When he correctly answers a trivia question on the radio, Mac wins the chance to take a shot from center ice at a Philadelphia Flyers game for a weekend at the station's beach house. While Charlie trains Mac, Frank, Dennis, Dee take their bar-banter to the Internet with their own podcast.

The Gang tries to get into a fancy upper-class swim club but discover that it is "at capacity"--for them. Dennis and Dee try to convince Charlie and Mac that they are upper-class by pretending that they got into the swim club when they really had to settle with the disgusting public pool. Meanwhile, Mac and Charlie try to fix up their old neighborhood diving pool that is now filled with trash.

Charlie and Mac try to get their mothers to live together in Mrs. Kelly's house after Mrs. Mac burns hers down. When Dee gets sick, Frank tries to take care of her (with Dennis' help) with the ulterior motive that she will take care of him in his old age.

Dee freaks out the Gang when she announces she's pregnant and one of the guys is the father, and they enlist the help of Frank, Artemis, and even the McPoyles to recall their last Halloween party, where Dee claims it happened.

The gang opens a time capsule and tries to make good on the past: Dee takes another shot at acting by visiting her old drama teacher and ends up teaching his unmotivated drama class; Mac, Dennis, and Frank try to get their old gang member Schmitty back into the Gang but Charlie gets jealous of Schmitty trying to replace him so he becomes the janitor at the school Dee is teaching at and claims that they are best friends. Guest stars Jason Sudeikis and Dave Foley.

Motivated by the drama teacher who inspired her, Dee takes a job as a substitute teacher, and exposes her students to the culture of Paddy's with a field trip to see the Gang's take on the Lethal Weapon series: Lethal Weapon 5.

Keeping the basement rodent-free drives Charlie to the brink, so Frank encourages The Gang to throw him a surprise party; they get into a frightening situation with "bridge people" and scrap Frank's plans, and use Charlie's "dream book" to plan the party.

The gang travels to Atlantic City for a charity benefit. When the car crashes into a tree because they were trying to avoid hitting a squirrel, Mac, Dee, and Frank must survive in the woods while Dennis and Charlie hitch a ride to the city. When they get there they pretend to be Frank and Mac and have the night of their lives flying on a private jet and meeting Chase Utley, a baseball player for the Philadelphia Phillies that Mac had long yearned to meet.

Dee's blessed event is fast approaching but the guys still don't know who the father is, so Mac, Charlie, and Frank invite all of Dee's former flings to a party while Dennis stays at the hospital with Dee.

After years of being mistreated by Frank during the holiday season, Dennis and Dee decide to teach him a lesson. Meanwhile, Mac and Charlie reflect on their childhood Christmases, and realize that they were not as joyous and wonderful as they remembered.