Laz Lackerson fears that his spineless father Rick and bossy step-mother are going to throw him out of the house at 19. Still he risks his hamburger joint job by standing up for co-worker Lily in front of his manager - but loses his job in the process. Wicked step-sister Molly's misbehavior decides the mother to keep Laz home as a good influence on her. Joining the hamburger workers solidarity, she meets student Jasper, who actually turns her near-human.
Laz's parents accept Mr. Hut's demand that he and his mates should work off their vandalism debt without pay. They discovering they can use the stand's produce to barter elsewhere in the mall. Then Laz gets them another sales job, which proves even more hellish almost literally. Jasper brings family and friends for what Molly assumed would be a private date.
When Fred surprises Mr. Hut shaving, the delicate marital balance breaks and he spends his evenings in the restaurant. Alas he expects his staff to join his entertainment, which neither dares refuse as childish. Frankie convinces his parents Laz deserves a reward for helping Molly. In fact she's taking his cue to rebel against the discipline-devoted German teacher, Herr Leonard Schmidt, thus making an impression on Jasper.
Fred has an eye on Allison, the sweetheart of the Sports City hotshot clerks, but she's their leader Evan's favorite. Laz tries to help him, but Evan wants a duel - with each of the non-jock boys. Fred accepts it's time to step up, but resorts to a desperate move: wear wacky glasses, with weird results.
The three mates enter a standing-and-touching marathon to win a car. Fred is out in seconds. Loyal Laz'z refusal to scrap his mate's share causes a row with Lily, so he's susceptible to foxy Jennie's flirtation. Meanwhile ingrate Molly decides to show her 'mean' parents how 'cruel' a surprise party is.
Lily finally gets Laz to make love, but cruelly dumps him over commitment semantics. Fred gets obsessed with edible underwear. The parents decide to make sure Molly's first experience with getting drunk is in a safe environment: home. Actually the minx is the only one staying sober, and learns about their wild youth.
Lily is getting obsessively intense, which stifles and frightens Laz, but he refuses to budge. Fred and Molly tell them, but they persist in playing chicken until they find themselves pronouncing wedding vows at a fake ceremony. They do this in order to get Laz's father's wedding pictures from a famous photographer. Meanwhile Molly hopes to get Jasper now that he dumped his ex, Susan, but he really doesn't know.
Fred gets horny on ma Michelle Lackerson's hands during hairstyling, but when he allows her equally horny friend Jeannie to fill in that becomes a physically mature relationship, for which neither is emotionally mature enough. Molly nearly ruins dad's PC, so she indulges Gus's caffeine addiction to keep her 'prefect' kid-step-brother quiet. Believing Lily dumped him, Laz wants to go all the way with her mate Sandy.
Eager to prove they're over each-other, Laz and Lily date Mr. Hut's intern Nancy viz. buns delivery boy Brad. Fred has a gig with things tied to clothes and ripping them off fast. Molly pretends to be heartbroken by a wrecked teddy-bear to get cable TV in her room as guilt buy-off, but here sneaky plan backfires.
Although it's their fault that Laz wets himself when the girls practically run over him, Molly and Lily keep bringing up the subject, yet feel guilty. Even Fred can't help laughing before commiserating with the victim. Gus starts smelling because he keeps wearing his school play 'knights armor'. Laz hopes to be cool again by sitting for 3 hours in the mall's Chinese restaurant crab tank. Things 'even out' surprisingly.
Jasper assures Molly his parents are nice, even easier to get on with than him, so they never fight - unlike his father's 'fire-breathing' mother. Still Molly is mortally nervous about meeting them, and - accidentally scares 'nanna' to death. Laz and Lily need a place to be together, so he gets a friend to let them sleep in his Beds store. Trying out test-beds is heaven for Fred, who also found a sick bird. However the couple finds their bed habits hinder each other from getting any sleep.
Fred got three tickets for the Beasty Boys concert and offers them to the boys who are fellow fans. Laz is determined not to go, believing fate will punish him and Jasper for bailing out on their promise to attend the girls' self-defense class demonstration. Their crutch kicking obsession scares the pants off Rick, and sees the boys literally pants down at the start of a roller-coaster of surprising turns, while fate seems to push them to the concert.