"You got like ten minutes of clean water and then every slide's basically a urine delivery system."
— Dee
While visiting a waterpark, Dennis decides to take on a protege in the form of a pre-teen hustler, Mac and Dee get stuck inside a water slide, and Frank and Charlie attempt to ride every attraction the park has to offer.
This episode provides examples of the following tropes:
- Adults Are Useless: The staff in charge of the water park couldn't give a damn about doing their job. The attendant in charge of the kiddie slide shrugs when Mac and Dee go down, despite previously warning them it's for children only, and he continues sending kids down without checking to see if the slide is occupied. The lifeguard is no better.
- Bait-and-Switch: When Dennis starts lecturing Abby on the criminal path that she's headed down.Dennis: I see the road you're headed down: the lying, the stealing, all of it. And as somebody who's been down that road, let me tell you something... you've got real talent.
- Bastard Understudy: Abby cons a bunch of people with Dennis and eventually uses these tactics on him.
- Blood Is Squicker in Water: The pool turns red with blood at the end of the episode after Frank flays most of the skin off his back going down a slide that hasn't been officially opened to the public yet and thus has no water to lubricate the way: this causes a huge panic since he's been going around telling everyone that he has AIDS to skip to the front of every line together with Charlie.
- Brick Joke: Mac repeatedly warns anybody within earshot not to sit on the pool drain, "no matter how good it feels". When everybody else is evacuating the pool at the end of the episode, he swims to the bottom alone and sits on the drain with an expression of pure bliss on his face.
- Call-Back: The unopened slide that Frank and Charlie discover is called "Thunder Gun Express".
- The Cameo: Game of Thrones showrunners D.B. Weiss and David Benioff appear as the apathetic lifeguards. The pair are longtime friends of the show and wrote the season nine episode "Flowers For Charlie".
- The Con: Abby's first interaction with Dennis is scamming him out of $20. Dennis, being Dennis, reacts by deciding to help her scam and steal from the park's visitors, then she plays on his ego by telling him he's the "only grownup who ever gave a shit about her," distracting him while she steals the key to the loot stash.
- Cool Shades: Played for laughs when Dennis caps off a Rousing Speech by dramatically donning the pink girl's sunglasses that he'd just confiscated from Abby, only to realize that they're much too small for him.
- Crazy-Prepared: Dee reveals that she's brought a urine testing kit with her in order to ensure that the water is clean before she enters it.
- Didn't Think This Through:
- The lifeguard tells Dee and Mac they can't go down the Kiddie Twister because they're above the height limit. They go down anyway and get stuck because the slide is too small.
- Charlie and Frank try to ride a slide that hasn't opened yet and has no running water. Charlie tries lubricating it by dumping the contents of a water bottle on it. Frank goes down the slide and most of the skin on his back gets ripped off due to the friction.Frank: Aaaahhh! It burns it burns IT BURNS IT BURNS! AAAAAAAAGGHHH!!! MY BACK!!!
- Dissimile:Dennis: If you were born in China, you'd be the head of some factory by now... or they would have thrown you in a river 'cause you weren't a boy. Alright, it's not a great analogy.
- Do Wrong, Right: Dennis claims Abby is a common thief and says she could instead be an artist, which Dennis defines as someone who "takes whatever he wants when somebody's looking right at him." Of course this is, in fact, exactly how Abby scammed $20 off him, and how she later steals the locker keys.
- False Rape Accusation: Abby threatens Dennis with this after he thwarts an in-progress theft:Abby: Try to touch me and I'll cry rape.Dennis: Oh, please.
- Flashback-Montage Realization: Towards the end of the episode, Abby announces to Dennis that her mom will be saying it's time for her to go and she gives Dennis her watergun to remember her by because he has actually "given a shit" about her. Dennis then goes to confront the mom, only to find out that Abby as lied. He then has a realization that Abby has used the watergun moment to take the locker key from his wrist and steal everything which they have accumulated over the course of the day, using his lesson about stealing in plain sight against him.
- Have I Mentioned I Am Heterosexual Today?: Fearing he will be Mistaken for Gay, Frank assures the parkgoers that he has "the vagina" kind of AIDS and not "the gay AIDS."
- Help, I'm Stuck!: Mac and Dee spend the entire episode stuck inside a water slide with a growing number of kids piling up behind them after ignoring the attendant's warnings that it's only intended for children aged twelve and under.
- Incest Subtext: At one point Charlie proudly claims he gave Frank hickeys in order to better sell the "lesions" from his "AIDS" — which would be squicky enough on its own, but given that Frank is heavily implied to be Charlie's biological father...
- Little Miss Con Artist: Abby uses her youth and innocent appearance to gleefully scam the adult visitors at the park.
- Oh, Crap!: Dennis's reaction when he realizes that Abby has stolen the key to the locker where they stashed all their loot.
- Pet the Dog: The episode has several humanizing moments for Dennis, who seems to genuinely care for Abby in his own twisted way, even going so far as to lecture a woman he believes to be her mother about treating her better. Even after discovering Abby had conned him he still seems impressed rather than angry.
- Playing Sick: Frank and Charlie pretend that Frank has AIDS in order to get to the front of all the lines.
- Politically Incorrect Hero:
- Frank assures everybody that he doesn't have the "gay" AIDS.
- Dennis states that if Abby were Chinese, she'd be killed as an infant and later has to ask about any cultures that value women.
- Ripped from the Headlines: Much what happens in this episode seems based on incidents at New Jersey's notorious Action Park, which closed the year before the episode aired and had a twisted cult following, particularly among comedians. The small details match: People got repeatedly stuck in water slides, sometimes ignoring posted rules; multiple children drowned; multiple children were found gushing blood in the water. Frank's back injury combines two of its most notorious rides: Action Park's Alpine Slide, described as "essentially a giant track to rip people’s skin off that was disguised as a kid’s ride"; and the Cannonball Loop, a quickly-closed ride where park employees "ensured" riders' "safety" by spraying them with a garden hose and sending them down the slide.
- Seen It All: Frank & Charlie run into Dennis & Abby part way through the day; Dennis immediately figures out that Frank is pretending to have AIDS, and Charlie in turn figures out that Dennis is doing a 'fake daughter thing'.
- Shout-Out: When Mac swims into the bloody water, Dvořák's New World Symphony
begins to play, referencing the derivative Jaws theme. - Surpassed the Teacher: Dennis decides to take Abby under his wing as a budding con artist after she "convinces" him to give her money by posing as his daughter in front of a mom he was trying to pick up. At the end of the episode, she succeeds in scamming him again, stealing the key to the locker containing all the items they'd stolen throughout the day. Upon realizing this, Dennis seems to be more impressed than anything.
- Surveillance Station Slacker: A lifeguard by the kids' slide spends his day reading porn and barely glancing up, even as a kid is drowning.
- Suspiciously Specific Denial: Mac keeps warning everyone to keep their butthole away from the pool drain, even when no one was thinking of doing that. Of course, at the end of the episode, he does exactly that.
- Urine Trouble: Dee, Mac and several children end up peeing themselves while trapped in the slide.
- Unusually Uninteresting Sight: The lifeguard on duty doesn't even look up when he realizes that a man who supposedly has AIDS is bleeding profusely in the pool. He merely blows his whistle and instructs everyone to leave the pool.
- Vacation Episode: The gang spends the entire episode at the titular waterpark.
- What Happened to the Mouse?: Mac and Dee send down an unconscious child down the water slide they were stuck in, and he's shown floating face down in the water as the lifeguard on duty shrugs. He is not shown again. Made worse at the end of the episode when a woman asks where her son is.
