After being chased by a barber they thought was trying to kill them, K'nuckles says "Whew! I thought you were going to kill us! Now... do you have anywhere I can swab my poopdeck?"
The episode featuring Flapjack's diary literally gets "crap" past the radar at one point.
The writers also make it painfully obvious that K'Nuckles was drunk.
Flapjack: I'm keepin' a diary about it! It starts last night, with us going to the Candy Barrel, and YOU eating all the candy! And falling down! And saying that I was your only friend! And promising to take me on an exciting adventure!
K'Nuckles: It was a long night, Flapjack. I'm sure I said a lot of things.
When Bubbie says the peepholes in the dock were her friends and Flapjack questions her, K'Nuckles replies with: "There are all kinds of friends, boy!" (He pulls out a bottle of Maple Syrup and downs the whole thing. After, he shivers and stows the bottle in his jacket.) "There's all kinds of friends." (He pats the bottle through his jacket.)
In "K'nuckles Hilarious Problem" the candy-drugs connection was made pretty nightmare-inducingly explicit.
The episode "Skooled" features a gigantic octopus named Eight-Armed Willy. That wears an eyepatch. Willy. One eye. Think about it.
It also features a bunch of severed hands and feet surrounding a sleeping Eight-Armed Willy. There are even screams heard during this display!
In "Looking For Love in All the Wrong Barrels", K'Nuckles says, "I don't LOVE anyone. Not women, not men, not anything!"
The Beard-Off episode. Keeping the whole episode in mind, it's about a bunch of women in drag competing to marry a woman by showing off their talented beards. Also, it's not made clear whether or not Dock Hag married Candy Daughter.
Concerning the first part, they could have just been intending to eat her like Flapjack and K'nuckles were.
A bunch of women pretending to be men so they have the chance to "eat" a girl? A girl that's desperate for a mate? Think of what you will at that.
Flapjack's Catch Phrase 'Cannonballs' can also easily be taken as a G-Rated way of saying 'balls/bollocks'.
The episode Jar She Blows plays out like a fifteen minute long gay joke. Rubbing is involved.
Flapjack: All greased up and ready to enter!
From the same episode: "Now strip down to your undies and grease up!" *cue K'Nuckles's rape face*
Guy on island: Oh you've gotta be-.
Season 1, Episode 5/2, "Snarked" has this line from Flapjack: "But they're (Snarks're) just visiting sea-folk! Come to Stormalong for a little candy and *sly look* satisfaction!"
From "How The West Was Fun": "You can't drink seawater! Don't you know what fish do in it?!" From the mouth of Flapjack no less.
In the episode with the census pirates, the pirates go through a slideshow of their plans. It involves pictures of a pirate taking gold and a pirate carrying a woman onto the ship. That earns a rather large cheer from the crowd of pirates.
In one episode, the entire Candy Barrel gets filled with blood.
In "Mayor May Not", when K'Nuckles asks why the Dock Hag keep giving him tickets, she says "It's that time of the month!...I have to fill my monthly quota".
In "Off With His Hat" it is heavily implied that the woman studying, and living amongst, the chimps participates in beastiality. She is seen trying to kiss the chimps a couple of times!
In "K'nuckles' Hilarious Problem" it is made blatantly clear that K'nuckles is drunk off of candy.
There is even a montage of K'nuckles getting progressively more drunk! We hear this exchange early on: "Did I ever tell you you're my best pal ever?" "Yeah!" "Really? When did I tell you that?" "You tell me that every time you eat a lot of candy!" Slightly later we get treated to this: " I love you and Bubbie sooo much Flap!"
In fact, the whole episode is a giant metaphor for alcoholism! K'nuckles even says "I can stop anytime I want!"
In "Hand it Over", K'nuckles mentions what he does with one of his prosthetic hands: "I oil it every day!", and then, "I soil it every day!"
In "Oh, Brother", Flapjack asks Bubbie where babies come from. At first she stammers, then she says "I don't remember where babies come from", obviously to avoid the question. When he still persists, she tells him the story how she found him (he drifted on seaweed). He asks if babies come from seaweed, and Bubbie says yes. After he leaves, she breathes out and says: "I think that went rather well."