Four egocentric friends run a neighborhood Irish pub in Philadelphia and try to find their way through the adult world of work and relationships. Unfortunately, their warped views and precarious judgments often lead them to trouble, creating a myriad of uncomfortable situations that usually only get worse before they get better.
Mac finally gets his big break after correctly answering a trivia question on the radio. While Frank, Dennis, and Dee take their bar-banter to the internet with their own podcast.
Rejected from a pool club, Mac and Charlie set out fix an abandoned pool to help cope with the Philly heat wave. Meanwhile, Dennis and Dee go about dealing with the heat in a different way.
Mac's mother is left homeless after she burns down her house, which leaves Charlie and Mac with no choice but to make new living arrangements; when Dee feels under the weather, Frank tries to muster his paternal instincts to care for her.
The gang gets a real scare after Dee reveals she's pregnant, forcing the guys to recall their last hazy Halloween party to determine who the father is.
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.
Dee's blessed event is fast approaching but the father's identity remains a mystery---to the gang, at least. So they throw a party and invite all of Dee's former flings.
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.