Jimmy’s science project is late, because his parents made him go with them to a Ramones’ concert. When Sean pleads Jimmy’s case with the principal, he only succeeds in getting Jimmy thrown out of school.

Jimmy's claim of demonic possession and Lily's skirt length prompt Sean's perceived battle with school head Sister Helen

To save for a dream vacation to Mexico, Sean and Claudia start working extra shifts at work. This leads to chaos at home, with Eddie raising the kids, Lily getting her tongue pierced, Jimmy becoming a bully, and Henry panhandling and eating out of the garbage.

When Lily is miserable because she and her girlfriends have been booed off the stage at the school's talent show, Sean and Claudia have some explaining to do. Meanwhile, the Finnerty's get roped into buying cases of candy bars that the boys are selling for school.

Claudia is shocked to find some racy pictures downloaded on Jimmy's computer, and insists that she and Sean confront him about it, but Sean wants to ignore the situation. Later, Sean confesses to Walt that he downloaded the pictures, and its not long before Claudia discovers that Sean is the guilty culprit. Meanwhile, Lily gives Jimmy a picture of Sister Helen which they doctor and use as an e-mail joke. But when the e-mail is sent to Sister Helen, things aren't so funny anymore.

While Sean and Claudia are chaperoning at Lily's school dance, Sister Helen catches Lily and Dean red-handed with a bottle of liquor while they are making out. Lily insists she is innocent and that the booze is not hers. But it comes as a surprise to both Lily and Sister Helen when the real culprit is revealed. Meanwhile, Eddie has taken to using Walt as his goon to shake down his shady business associates.

Sean exploits a nun's foulmouthed slip of the tongue to get Claudia and the kids everything they've ever wanted from St. Finnian's.

Sean winds up in jail for buying some shady diamond earrings for Claudia from Eddie's so-called ""connection""; Lily protests the nuns's donkey-basketball game.

For the second time, Lily has failed her behind-the-wheel exam. But this time it's not her fault, it's Sean's, who went out of her way to sabotage her driving test by teaching her rediculous driving tips, such as the all-important ""W-turn."" In other events, Claudia is having a devil of a time keeping Henry and Jimmy from playing a violent video game condemned by Sister Helen -- but she winds up addicted to it herself.

From TV Guide: Following his school's drug-awareness day, Henry thinks his family is on drugs and stages an intervention for Sean after he finds a suspicious plant growing in the yard.

Sean and Claudia are shocked to learn that Jimmy has been shoplifting and try to figure out his motivations for stealing. Elsewhere, Lily agonizes over what to wear for dinner with Dean's parents. Brad helps her find the perfect outfit, but Dean's parents turn out to be not so great. Meanwhile, Henry brings home his class's pet lizard.

Brad is bothered that Lily is embarrassed to be seen with him, so Sean tries to make over his geeky image. But all Sean succeeds in doing is inadvertantly getting another student suspended from school... Which leads to an in-bar confrontation with Sister Helen. Meanwhile, Jimmy's ""trademark"" hair-length has become an issue at school. Elsewhere, Claudia helps Eddie deal with an unwise purchase he made for the bar -- by getting drunk with the customers. And Lily confesses her relationship with Brad in front of the entire school.

Lily, Brad and Jimmy sign abstinence pledges at school; Brad asks Lily to marry him; Jimmy throws out everything that reminds him of sex. Meanwhile, Walt reveals that Eddie was born lefthanded.

Sean disciplines one of Henry's bratty friends; Lily asks Brad to choose between her and his geeky friends; Eddie uses a Jewish online dating service.

Sean's old friend Dave is in town, a children's performer who goes under the name ""J.J. Bodybuddy"". He lets Dave stay at his house...but it isn't entirely altruistic. He's promised the school that he can get J.J. Bodybuddy to do a show for the kids. The problem is, Dave--a recovered alcoholic who hasn't touched the stuff in ten years--gets too drunk to do the gig, and Sean has to put on the Bodybuddy leotard hismelf. Meanwhile, Lily is jealous of the new baby, and is letting her feelings be known vociferously.

Sean becomes infuriated after receiving letters from the Home Owner's Association telling him to clean up his house, while Claudia is happy about the positive changes to the neighborhood. Meanwhile, Lily insists that Brad buys her an anniversary gift from a list that she's made... but he defies her wishes and gets her a sexy nighty... that he can't enjoy because he's busy picturing Sister Helen, who he ran into at the lingerie store. And Jimmy shocks the family by making an unusual lifestyle choice -- he announces that he's a vegetarian.

In the series finale, Claudia and Sean miss Lily's graduation (thus spoiling Lily's senior-prank plan) when Claudia goes into labor. Meanwhile, the Finnerty boys learn that Walt has a girlfriend... his cleaning lady!