The possibility of Leonard and Penny getting back together could prove to be disastrous when Leonard offers Penny a spur-of-the-moment invitation to dinner.
Sheldon makes selfish demands that force him and Leonard to reconsider their long-time friendship; Howard is in the process of picking his astronaut name.
Phil thinks that Gloria is unhappy with Jay for a mistake on Valentine's Day; Mitch and Cam may have unintentionally ruined Luke's date for Valentine's Day.
The family sets out on a wine tasting adventure; Gloria and Mitch are invited to a party at Oprah's house, but they are not allowed to bring anyone else.
Haley's smart boyfriend arrives to meet the family; Mitch and Cam set out on a yoga retreat, but Cam discovers his dream team's spring training is next door.
Gloria's ex-boyfriend's striking resemblance to Manny leads Jay to wonder if he might be Manny's biological father; Lily gets into a fight at school over bras.
When Haley finds out that her boss is searching for a product with the magical elements of peppers, she attempts to convince Gloria to sell her salsa to NERP.
Plankton becomes a ghost to steal the Krabby Patty secret formula, but it requires a few lessons from the green-glowing pirate ghost, the Flying Dutchman.
A criminal mastermind decides to use three orphaned girls to pull off a big heist, but when their love warms his heart, he considers abandoning his plans.
Members of a spooky and mysterious family begin preparing for a visit from their even creepier relatives, but trouble starts to brew with a TV personality.
SpongeBob accidentally puts all the residents of Bikini Bottom on Santa's "naughty" list as part of one of Plankton's plots to get the Krabby Patty formula.
The guys are uncomfortable with Carol's breast milk; Rachel is uncomfortable with Monica's growing friendship with Julie; Joey works as a cologne salesman.
The gang is amazed to learn that Phoebe married a gay Canadian ice dancer to help him get his green card; Ross seeks sexual advice from Rachel regarding Julie.
Chandler and Joey baby-sit Ross' son and accidentally lose him while scoping babes on a bus; Phoebe loses her Central Perk singing gig to a professional.
Sheldon is forced to use his vacation time, so he goes to work with Amy in her neurobiology lab; Bernadette wants Howard to think about signing a pre-nup.
Sheldon clashes with his nemesis Kripke at work when an office at the university opens up; a gift from Amy makes Penny feel uncomfortable with the gesture.
Dede's unexpected appearance makes Mitchell and Cam realize the effect that she has on their lives; Luke, Phil, Haley and Alex all have bad news for Claire.
Haley meets Arvin's parents; as Jay, Mitchell and Claire compete to get time from Jay's sister, Phil, Gloria and Cam get trapped in the home's basement.
Haley seeks some advice from Mitch and Cam about whether she should tell Arvin about her kiss with Dylan; Gloria suspects that Manny's girlfriend is made up.