Finn was in the middle of his usual daily routine, he got up, got dressed, brushed his teeth, and went down stairs and was greeted by the sight of his best friends, Marshall Lee and Fionna, making out. Oh yeah, this fanfiction takes place 1 year (maybe 2 years?) since the time Adventure time currently takes place, therefore Finn and Fionna are both sixteen, anyhow, in the time that has passed they managed to open a portal between Ooo and Aaa using the powers of fanfiction logic, and Marshall and Fionna are dating now, so that also happened. Back to the main plot though.
"get a room u to." Finn said. "we have room, itz called ur house!" replied Marshall.
(Oh, I forgot to mention that I'll will be writing all of the dialogue in terrible grammar and spelling, because I''m already running out of ideas on how to right a parody fanfiction. I will also be including the occasional mind- numbingly stupid urban slang term that dosen't actually exist in the AT universe but I'll include it anyway because why the fuck not.)
"qwiet u biches! im trying to beat flappy bird on mah iphone that shouldn't actually exist." Said Fionna. Marshall than remembered what he and Fionna were put in this fanfiction to do and began making out with Fionna again.
Finn continued his daily routine and got in his ferrari that he got using fanfiction logic and drove to the nearest Starbucks (that's right, I dragged that in too) for breakfast. After he ate breakfast he got back into his car and drove to Ooo high school that he goes to now and all the other characters on adventure time go too even though most of them are to old to go to high school and the ones that are old enough just don't go to school, but why the fuck not. So Finn got to his locker and met with his friends like Marceline, Jake, Princess Bubblegum, and much much more. He talked to his friends for a while and then he went to see his girlfriend who was one of the many OCs that make up 90% of the school because there weren't enough characters to begin with.
He said "Hey Finnona whatz up?" (His girlfriends name is Finnona because whenever a character dates an OC it's a law that there name has to sound similar to the character they're datings name). "Noting baby i wuz just wonduring if u want to go make out, smoke weeed,and other things in teh janitoors closet since there arent any reaal janiters aroound here?" replied Finnona. "sur babe i titally wnat to do all dat stuff" Answered Finn. After a few hours of making out because, let's face it, no one actually learns anything schoolwise in these crappy high school AUs. "Itz tyme for luunch babe so we shold go shit with our friensds" said Finn, "butt eye cant cauze im two fatttttttt!1111!" replied Finnona. "Baby ur not fat ur butiful", "Realy Finny Winny?/?", "yeah babee". And with that the two continued making out for several more hours until they finally stopped when coincidentaly school also ended (isn't it funny how there's no school in the school).
The two walked outside holding hands when they were stopped when the self proclaimed school bully Tiffany stepped directly in their path. "Sooo Finnona i see ur still hanged out wit this lOooser Finn!" uttered Tiffany. "At lest he doesnt have facial hare an sound lik a girl!" rebutled Finnona. "Hey, dont talk to Tiffany tat way, tiffany iz 2 cool for dat biatch" he said he stepped slightly closer to Finnona. "Hey,get away from her u dingus!" Finn said before he punched Tiffany in his face, "Did he hurt u my sweat!?". "no my babae, luv u because u protect me!" replied Finnona (I can already imagine the social justice warriors raging at me in the reviews saying "just becuze shes a woman dosnt mean she cant defend her self u sexy sexist pig!"). The two walked over towards their friends leaving behind Tiffany who was now on the ground crying because he just soiled himself because of the awsomness of Finns punch.
"Hey Finn nise goind over der wit tiffany u showed his punk ass!" Said Marceline as she fistbumped Finn. "While u no it wuz noting, anyway i gotto give finnona a ride too her home so u no i gotta goe!" shouted Finn. "Bye!" all of their friends shouted in completely perfect unison so instead of sounding mundane it just sounds really weird because of the way it was written (if you can't tell right here I'm making fun of how in some fanfictions it says multiple characters say something to one character but the way it's written it seems like they all say it the same time in unison, that really grinds my gears). "Letz take a groop selfie before we go!" said Finnona. "Okay" everyone once again shouted in unison.
So with that Finn took his girlfriend home and went back to the treehouse to work on the homework he dosen't have because the author of every high school AU I've ever seen has clearly never actually been to high school.