Tonight's lesson: Karma's a bitch. Just ask Sean: he sooo wants to make this year's family Christmas card a standout, and he's go the perfect '50s motif: he'll be the closeted dad while Ellie will be the rebellious daughter who's secretly dating a Jewish boy. But Ellie wants nothing to do with it. But holiday cards are serious business to Sean, and he tells Ellie she's doing it whether she likes it or not - a child must respect her parents. Cue Lorna. She's lost her ballroom dance partner due to injury and has come by to enlist Sean to join her as she competes for a third consecutive club championship. Filled with horrible childhood memories of dancing with his uber-critical mom, Sean wants nothing to do with it. Of course that's not lost on Ellie. If Sean won't obey his own mother's wishes, then Ellie shouldn't have to obey her dad's. Sean, hell-bent on that Christmas photo reluctantly agrees to join Lorna on the dance floor.
One disastrous dance session with Lorna is all it takes for Sean to realize his mistake; his mom just can't stop criticizing him. In the break room, Liz suggests that Sean fake an injury and then get someone to substitute for him. Hunter volunteers for the assignment - if Sean will handle his most irksome customer. Sounds like a plan. All Sean has to do is invent an injury and act the part. Max gets wind of the scheme and is deeply hurt he wasn't asked to fill in for Sean with his mom. Among his many talents, Max is also an expert dancer and choreographer. (Who knew the U.S. Army had a staff of choreographers?)
Back home, Ellie thinks that since her dad's faking a foot injury to get out of his duty to his mother, she should be able to skip out on the Christmas photo. Sean tries to explain that it's different - even though it really isn't. Lorna pops in with Hunter, exhilarated after another terrific dance session together. Lorna showers Hunter with praise for his mad skills. Sean burns. He sends Hunter on his way and then confronts his mother as to why she's praising Hunter even though she knows Sean is a much better dancer. Lorna scoffs, incensing Sean. Sean tells his mom that he's going to find a dance partner of his own and beat his mother at the contest!
Sean enlists Liz as his partner and Max as their choreographer. Max's psycho, telling them they will win or die trying. After a few whirlwind rehearsals, the big night arrives. Liz looks smashing in her red evening dress; Sean sports a sassy sash for a belt. Max couldn't be more proud, offering Sean a gift of a pen as a token of appreciation for his preparation. But Sean drops the pen, and as luck would have it, both he and Liz bend down to get it; Sean's head smacks Liz in the nose. Seconds later she slips on the floor, injuring her ankle. And of course, the two of them are called to the dance floor to follow up on the magnificent performance that Lorna and Hunter have just turned in. Quick as a cat, Max comes to the rescue. Moving with a grace and a precision honed by years dancing in the Army, Max partners with Sean in a fluid, flawless tango. The trophy is theirs!
Lorna congratulates her son on his victory, much to Sean's incredulity. She explains that she's always wanted to see Sean succeed - and her technique has always been to push him harder and harder until he becomes the best he can be. Sean's touched. He shares a dance with his mom, just as Ellie stops by to witness that she's lost the moral high ground. It's time to pose for that campy Christmas picture after all.
When Lorna insults his dancing skills, Sean declares a war on the dance floor.