This is a AU (a August is a alternate universe) in this AU dipper is 15 same as Mable,
everything that went down in gravity falls still happen but in this AU dipper knows how to play the acoustic guitar,
the things is he only plays it when he's depressed only Mable knows,
but not for long when a friendly red head finds him on the roof and she is sad to her best friend like this. P.S this takes place after (time traveling pig) enjoy.
dipper pov "these gots to be the worst day in my life" Dipper thought to him self seeing his crush go on the tunnel of love with "Robbie" "he just had to come out of nowhere with that stupid snow cone" Dipper thought.
then a over joyed sister tackled him " THANK YOU DIPPER, THANK YOU DIPPER, THANK YOU!!!" as she holding him in a bear hug barley getting any air. as Dipper feels the life gets squeezed out of him ( literally ) the only word he can say are " mab... le... ai..r... "gasp" can't.... breath" as he struggles to breath, Mable finally let go of her dorky brother smile wide and picks up her pet pig waddles next to her.
dipper him self couldn't help him to put a small small on his face for what he did for his sister, but that smile didn't last long till he see wendy and Robbie walking together holding hands this caused dipper to flinch as she walk with him, dipper sighs trying his best not show one tear,
Mable see his expression and looks to where dippers eyes are glued she starts to feel bad for him Cuz sacrifice his chance to get his crush for her.
she looks back at dipper who has his head down now and the thing Mable can do is hug him as tight as she can and apologize to him " Dipper, am so sorry" as she holds him she can hear him sniff a litter bit but he stops and broke apart from the embrace and wipes the tears from his face and breaths in and looks Mable in the eye and tells her "Mable, don't be sorry for me... be happy I did that for you I can't see my twin in so much misery... besides wendy can't date robbie for the whole summer right" as he puts on a small smile on his face tell his sis that he's okay,
but Mable didn't buy it she can see how hurt he is just buy looking him the eyes she was ready to protest but dipper immediately stop when he puts a finger on her lips and tells her "Mable, am fine... I just.. need some time alone" Mable new by he meant by it,
he has going to play guitar again, but she knew he was right he just needs time and if means he has to go though depression she knew he will be over it a lot fast if he plays is acoustic guitar,
so the only thing she can say is "alright" as dipper walks away he takes one last look a wendy and Robbie,
he just sigh and continues to walk to the shacks front door, he's greeting by a friendly handyman named soos "sup dipper, hey I thought you where hanging with wendy?" this of course made dipper flinch at the thought wendy and Robbie so instead saying something dipper just remain silents and just walk past soos to his attic room, soos is dumbstruck at this Cuz dipper never ignores him,
as he was ready to go talk to him he takes a look out side and sees wendy with robbie holding hands,
after seeing this he immediately knows what's up as he looks away he sees dipper holding a acoustic guitar as he head to the ladder to roof where he can be in private but soos puts a hand his shoulder and say "are you good dude" Dipper turn a his head over his shoulder and says "am fine, soos... don't worry about me, go have fun outside I just need to be alone right now, thanks for asking tho" soos just nods and let him be as dipper make his way up the way up the ladder he opens the hatch and walks to the edge looking down at everyone and he spots her in a instance so sit on the edge of the lounge chair and starts tuning his guitar after he's done he thinks for a minute before he knows what to sing
wendys POV
"Robbie's a pretty cool dude, to be honest I was litter shocked when he ask me out but guess I should give him a chance, like we been friend since grade 9"
as wendy and Robbie where hang out robbie said
"hey wendy u wanna go hang with guys"
wendy of course thought for a moment before saying
"sure, why not, you get the van I'll go get my jacket I don't want to leave it again"
as she walks to the shack she totally remember she just ditch dipper "wow I can't believe I just forgot about him, ugh.. I hope he's not mad at me"
she continues to the shack, when a certain brunette came up to with a big saying
"hey wendy, look at my new pet pig, you know what I named him I'll give you a hint, it starts with a w.. and end with addles"
wendy just smiled at this and chuckled before saying
"yo dude, that's so cool, but I was wondering if seen dipper I need to apologize for ditching him"
Mable just looked at her before she spoke again
"nope sorry, I seen him earlier tho I think he's inside"
Mable hates lies but she thinks wendy should talk to her brother, wendy just look at her like she hiding something but she shrugs it off and leave before she thank Mable as wendy went inside to look for dipper and find her jacket looks at the ladder and sees that the curtain open and a light coming from it,
she started climbing the ladder by half she can here a beautiful melody she get to the top and she see dipper play on acoustic guitar,
looking so depressed like hey lost a relative,
well that was until he started singing I don't want to be awake again,
  I spend my days with my head in my hands.
  If I go outside I'll fall apart.
  I am mostly scared of passing time, 
the world it seems gets more unkind.
  Inevitable tragedy will soon be mine. 
as he sing and play the guitar I hear in his voice how he sounded so hurt and as he hums before starts the next versus I look at his cheeks and I can see how he was steaming tears down his face
I am looking for an easy place, 
to mask my thoughts behind my face.
  Oh brown baked column of victory. 
Maybe I should just pack up and run away again, 
and let you forget that you where once my friend. 
Then watch another go on and do better without me.
  these time he put his head down, keeps his eye closed before looks up and continues singing But I could not go away,
not if I wanted to. 
I can hide from friends but I cannot hide from you.
  These chemical reactions are dividing me. 
Self-deprecating thoughts are interrupting all the time, 
emphasizing all the traits that I wish weren't mine. 
They speak louder than everybody  I try to keep my eyes closed as my outlook isn't bright, 
compulsively complaining when I haven't got the right. 
I hate the way that I think and act.
  I want to end reality but I feel hesitant, 
optimistic that the future will be more concerned than the present,
  and so for today I'll remain intact.
and like that he strums the guitar one more time,
he sniff once after taking a breath and put the acoustic guitar beside him and wipes the tears from his face,
then he lays on the lounge chair before passing out because of the crying made so exhausted.
as wendy Cuz look at him she felt a wave of guilt hit her,
just looking at her best friend so sad, she thought to herself
"did I do this, I must have I totally forgot about him now he's hurt, what kind of person am I"
she felt like crying because but she didn't she just look at him one last time before climbing back down and grabbing her jacket and heading out side to Robbie's van, as she hopped in robbie ask her something "hay babe what took you so long, that geek hold you back"
wendy just scoffed at that comment and told him
"no robbie it just took me while find jacket and don't call him that he gots a name"
Robbie was taking back at that and said sarcastically
"whatever"
as they drove off wendy couldn't get that image out of head of seeing dipper so sad and hurt she was so deep in her thoughts,
she ignored robbie and she didn't even notice till tambry snap her out of it "wendy, wendy, wendy!"
as wendy was finally snap out of her thoughts she look at tambry was like always glued to her phone,
seeing lee and nate still daring Thompson to do stupid stuffstuff like always, I look at tambry and say
"oh sorry, totally zoned out there, so what's up"