I dunno if you're still doing this, but I wish you could write a fic where both mabel and dipper keep dating people that look progressively more and more like the other until they finally realise that it's because they want to date their twin
Gravity Falls [OneShot] – (Pinecest) Other Side of the Mirror
“Hey, can you help me with something?”
Mabel pokes her head into Dipper’s room. Dipper looks up from the textbook he was reading, giving her an inquisitive look.
“Hm?” he said. The pen that he had previously been chewing on fell out of his mouth and onto his desk.
“If you’re busy, I can-”
“No, no!” Dipper said. He stretched, then shut off his desk lamp. He swiveled his chair so that he was fully facing the door. Mabel stepped inside and shut the door behind her. She was holding one of her many scrapbooks to her chest. Dipper could just barely make out the words Failed Romances written out in glittering purple ink.
“Boy troubles?” he asked. Mabel shook her head.
“Need to vent about the past or something?”
“Something like that,” she said, walking over to him. She opened the book and set it on his desk in front of him.
“You remember Zach, right?”
“Blue-ish blonde hair, plays electric violin, dumped you like three months ago for the girl he was playing a concert with? Yeah, what about him?” he asked. She smacked him lightly on the arm.
“Bad. That part I buried deep down in the pits of my memories. How dare you make me remember that.”
“I want you to compare him to my first boyfriend.”
“Avery? No, wait, are you talking about Norm-”
“Not the gnomes, you dork. Of course I meant Avery,” she said, flipping back to the beginning of the scrapbook. Mabel’s first official (normal) boyfriend leered at Dipper from behind the laminated page.
“This guy was a total jerkwad. Remind me why you ever agreed to date him?”
“It’s not my fault 15-year-old me thought he was cute. I was trying to not date for a while, but I ended up getting pulled back into the romance zone once again. Tragic, but that’s beside the point. The point is, compare him to Zach, please.”
Mabel watched as Dipper flipped between the two pages, trying to compare and contrast the two photos.
“Nope, not seeing this one, Mabel. Are you sure you’re on to something?”
“Not just on to something. More like discovered something really freaky.”
She pulled out her phone and opened the photo app. She had taken pictures of all of her ex-boyfriends, in chronological order, from Avery all the way to Zach.
“Are these all from your scrapbook?”
“Shush, I’m getting to the freaky part, bro. Watch.”
Mabel switched over to another app.
“This is one of those ‘photo-merging’ apps. You know, the ones designed to see what you’d look like fused with someone else? So I was messing around with Avery and Zach’s photos to see what they’d look like fused, and this came up.”
She pressed Fuse and showed him the results. Dipper stared at the screen. The app had taken common features from the two faces to create a fusion of the two, and the fusion looked eerily similar to Dipper. Granted, it had blue-brown hair, but the facial features were shockingly similar to his.
“What the heck?”
“Wait for it.”
Mabel started choosing random exes and putting their photos into the app. This fusion had Dipper’s eyes and his chin, this one contained all his facial features, that picture looked a bit like Dipper mixed with a dog, but all of them had at least one part of his own face.
“And now …” Mabel said, switching the settings. She mass-selected all of the ex-boyfriend screenshots and his Fuse. The app slowly loaded, trying to process the multitude of photos that had been selected. Finally, the app finished.
“Yup yup, bro-bro.”
The likeness was almost terrifying. You could see the blurred edges where the app tried to blend features like the hair or ears, but the face itself was clear, as if he was staring into a mirror.
“Okay, that’s just scary, Mabes.”
“I know, right? Why do you look like all of my ex-boyfriends combined, Dipper?”
“How the heck should I know? I should be asking why do all of your ex-boyfriends combined look like your own brother.”
“I dunno!” Mabel said, closing the app. “I mean, I guess I’ve been unconsciously choosing guys that sort of … look like you, or have something that reminds me of you?”
“Is that, uh, supposed to mean anything?” Dipper asked.
“That’s what I was trying to ask you, Dip. What do you make of all this? Put your smarticles on and solve this conundrum.”
“There’s nothing really to figure out, Mabel. You have just been dating guys that weirdly look like me in one way or another, and then when fused together they make a perfect image of me.”
“Ugh, you’re no help.”
“Unless you really like guys that look like me, you’ll need to either clone me or date me, ‘Bel,” said Dipper, chuckling. Mabel glared at him.
“Very funny Dipper. Hold on, lemme see your phone!” Mabel said, grabbing his cell from his desk.
“Shush, you,” Mabel said, scrolling through his phone. She used her own phone and started taking pictures from his photo library. “I knew you’d keep your own collection of sorts.”
“Yeah, but I don’t have your scrapbooking skills, sis, so my cell phone had to do.”
“Why’d you keep Wendy in this folder? You never even got to go out with her.”
“Uh huh, sure,” she said, adding Wendy’s photo to the snapshots.
Mabel started to put all the photos into the face-merge app.
“… then Jenna, Emily, May, aaaaaaand Wendy. Fuse!”
Mabel stared at the screen, for once at a loss for words.
“What? Let me guess, all of my ex-girlfriends plus Wendy equals your face,” said Dipper, looking down at his study guide.
“No way,” Dipper said, grabbing his phone.
It was definitely Mabel, down to the red highlights in her hair that she had put in last week. Dipper stared at his sister, and then at his phone once more.
“What’s going on? Why are we dating people that look like each other?”
“Again, you’re the smart one. Plus, I wasn’t expecting your exes to do the same thing as mine.”
“You sure that app’s accurate?” he asked, looking through the settings of the app.
“Well, what then?”
Mabel shifted her weight between either feet, taking her time to come up with an answer.
“Um, Dip, I think we’re dating people that look like us because we … like each other?”
“That’s the solution you came up with? You have a crush on me, Mabel?”
“I mean, it kind of makes sense. We spend so much time together, and we’re basically best friends. You comfort me when I’m sad, and I help you get a grip on reality whenever you have your anxiety attacks. Plus, they say that people are attracted to people that look like themselves in some way, so I guess with us being twins …”
“You’ve got a point, but Mabel, isn’t that …”
“Think about it, Dip. You think I’m pretty, don’t you?”
“Yeah, I mean, you’re beautiful, but …”
“B-Beautiful?” Mabel said, blushing. Dipper stopped mid-sentence, staring at her flustered expression. It was so similar to so many of his previous girlfriends that he felt his heart skip.
“I-I mean, yeah, I t-think you’re p-pretty, but I’m not sure how we can just have a crush on each other …”
“It’s kind of weird to think about, but … I think that it just makes sense.”
“Mabes, I don’t know what to think. I-I think we need some time to think about what this means.”
“Alright, I guess. I’ll be in my room, then, Dipper,” said Mabel, putting her phone away. She walked into the hallway, glancing at him as she shut the door.
Dipper let out a breath, and then looked at the screen of his phone. The gallery of his failed relationships stared at him. He pulled up a photo and started scrolling through the faces. This girl had a smile similar to Mabel’s, this girl had braces back when they were dating, and even Wendy’s face was starting to look more and more like his own sister’s face.
Oh God, Dip, get a grip! Don’t go thinking about how your sister’s face looks like people you’ve dated. Definitely don’t think about dating your sister! Don’t think about wanting to know what it’s like to fall in love with Mabel. Aaaaaand … too late, yup, you’re definitely thinking it. Definitely thinking it. Stop thinking it? Nope, thought’s still not going away. Fudge, this just got complicated.
Dipper dropped his head onto the desk and groaned. This was going to be a long afternoon.
Meanwhile, Mabel was still standing outside Dipper’s door. Her heart was racing, and her face still felt warm.
What the heck just happened? I came in there to ask about why my exes looked like my brother, and next thing I know, I end up suggesting that we like each other! My own brother! Have I accidently eaten something with Smile Dip again? Am I going insane? Should I talk to someone about this? I can’t talk about this with Dipper because that’ll make things awkward again …
Lost in her own thoughts, she didn’t realize that the door in front of her had opened, and Dipper had almost walked into her.
“Ack! D-Dip! What’re you doing here?” Mabel said, startled. She avoided looking directly into his eyes.
“I live here. Why are you still outside my door? You left like fifteen minutes ago.”
“Oh, n-nothing, nothing! Just sort of … thinking … about … stuff?”
“Mabes?” he asked, putting his hand on her arm. “You alright?”
Mabel stiffened at his touch, and turned her head until she was fully facing him. Their eyes met, and suddenly Mabel’s pulse rate went into overdrive.
Was he always this cute? I mean, of course he was cute, ‘cuz I’m cute and he’s my twin but … was he always this handsome? Why am I reacting this way? I see him almost every day. Am I overthinking things? I’m probably overthinking things. Oh no, he’s really close to me. Why does he have to be so dang handsome?
“Huh?” Mabel said. She blinked, then put her hands up to her burning cheeks.
“Let’s calm down over some ice cream, ‘kay? We should sit down and talk about all this,” Dipper said, gesturing between them.
“With sprinkles?” she said, chancing a glance in his direction. His smile put her at ease almost immediately.
“As many sprinkles as we can find in the house, Mabes,” Dipper said. He held his hand out, and Mabel took it.