After doing the story "Trust", I got in the mood to write another tale based on actual episode events... with a nice young Pines' twins headcanon flashback thrown in there. Anyway, this takes place in the last minute and right after A Tale of Two Stans.

What better way to start the new year?

Mabel's head was whirling everything that had just happened. It all went down so fast- one second, she was floating through nothingness, the next, she was on the ground and her grunkle's long lost twin was there. At first, she was ecstatic, thinking they'd get to all be one big happy family, but the four of them had just spent the day learning about how messed up the older twins' relationship was. And now, she was scared.

Mabel turned to face her own brother. "Dipper, you don't think we'll turn out like Stan and Ford, do you?" She hated herself for asking, especially when Dipper's expression turned to worry, but she had to get his thoughts.

"W-what do you mean?"

Mabel fell back on her pillow, looking towards the ceiling. "I mean, they used to be best friends, but then they got all stupid." She turned to Dipper. "Can you promise me you won't get stupid?"

Dipper's apprehension lifted and he laughed, figuring the best thing to do is joke to make her fell better. "Not stupider than you, dum-dum."

And it seemed to work; Mabel giggled. "Goodnight, stupid."

"Goodnight, stupid." Dipper clicked the light off and settled in his bed.

But Mabel's smile dropped as soon as he turned away. She stared up at the vaulted roof of their attic bedroom, mindlessly studying the cracks in the wood.

Surely, that couldn't happen to her and Dipper... they were their closest friends. He was always there when she needed him, and they'd helped each through everything. When her photo day was ruined, when he was left out on Valentine's Day... they knew just to do to help. So what was she so afraid about?

Because Stan and Ford were the same way...

Mabel shuddered at the thought. Stan and Ford, they were just like her and Dipper. Best friends, always there for each other, helping their sibling through the hardest times. But that didn't stop them from falling apart.

And now look at what just happened. Mabel had just chosen Stan over Dipper, chosen a man she had just had everything she thought she knew about thrown out the window. And yet she trusted him over her own twin.

Sure, he may have just been joking around with her, but deep down Mabel feared Dipper was upset with her. Upset that she didn't listen to him, that she hurt their relationship. Mabel felt tears sting the backs of her eyes, and she couldn't take it anymore. She turned toward her brother's sleeping form, watching the slow up and down motion of his breathing.

"Dipper?" She whispered. He didn't move. "Dipper!" She said louder.

Dipper shuffled under his blanket, still unsure if he'd heard anything. "M-Mabel?" He said, still half asleep. He turned over to see his sister sitting on the side of her bed, Princess Loveacorn clutched in her grip, staring at him with teary eyes.

"Mabel? Are you alright?" Dipper said, fully awake now, pushing himself into a sitting position.

"Dip-" Mabel began, but choked on his name, clearly to stop herself from sobbing.

Dipper clicked the lamp on and shuffled over to her side of the room. He barely got to sit beside her on the bed before Mabel broke down, burying her head in his shirt.

"I'm so sorry..." she bawled. "I-I was wrong... and you must hate me... and I'm just- just a horrible-"

"Woah, woah, Mabel, slow down!" Dipper said. "What are you talking about?"

"The portal, Dipper!" Mabel pulled away and tried wiping her eyes to no avail. "I-I chose Stan! After everything we found out about him, I trusted him... and I hurt you..."

Dipper didn't know what to say. He admitted, it did hurt when she chose Stan over him, and he had been angry that she seemed to ignore all his pleas for her to listen to him, but in the end, it was Mabel who brought the Author back. And Dipper was proud of her for that, for her seemingly unending empathy reuniting the brothers. He didn't understand why she thought he hated her, but he knew he had to make it right. Suddenly, a memory came to him.

"Mabel... do you remember the Twin Pact?"

Mabel looked up at Dipper, shocked; she hadn't heard him mention that in years. She sniffed and said, "of course I remember..."

...

Dipper and Mabel were five years old and about to start Kindergarten. Dipper was eager to begin this new stage of life, but Mabel was worried that school would hurt their relationship.

The night before the big day, after hours of pondering it, Mabel finally decided to express her fears to Dipper. She poked her head into his room to see him carefully setting out his first day of school outfit.

"Dipper?" She said, sounding quieter than usual.

He turned around, surprised to see her. "Yeah?"

Mabel took a deep breath to speak, but stopped, not sure how to explain her thoughts. Seeing the worry on her face, Dipper walked over to her and took her hand, leading her to sit on his bed with him.

"What's wrong, Mabel?"

"I- I don't know. It's silly..."

"That's okay."

"It's just... we're going to school tomorrow, and... I'm scared."

"Why?"

"I... I don't wanna lose you."

"Why would you lose me?"

"I don't know... because we won't be together all the time?"

"Yeah... but that just it. We won't always be together. We're different people."

"I know, I just- I love being with you. You're my best friend, and I don't wanna lose that."

"And you won't. You're my best friend too, Mabel. But we don't have to always be together for that to be true."

"Really?"

"Of course! We just have to trust each other to keep it like that."

"So... do you trust me?"

"I will always trust you."

"Me too... So it's settled then."

"What is?"

"We will promise to always be there for each other no matter what, even when we're, y'know, not literally there for each other. It's like... like our Twin Pact!"

Dipper laughed and playfully punched his sister. "That sounds dumb."

"So you accept, I see! Now we have to seal the deal!"

"With what? Like, a hug?"

Mabel giggled. "Ew, no!" She paused. "Well, actually... what's that word that Mommy always says with her brother? Ah-something?"

"Awkward?"

"Yeah, that one! How about an awkward hug?"

It was Dipper's turn to giggle. "Okay... weirdo."

The two embraced and Mabel said "Now pat each other's backs!"

"Oh, like this?" Dipper tapped her twice. "Pat, pat," he said sarcastically.

"That's perfect!" Mabel yelled, and the two laughed as their worries slipped away.

...

Mabel smiled slightly at the memory Dipper had brought up. "Yeah, I remember it... you said you would always trust me." She wiped the last tears from her eyes.

"And no matter what, we'll always be there for each other," Dipper finished.

"Mabel beamed for a second, then her smile slowly faded into a frown. "But... what about Stan and Ford?"

Dipper looked at his lap. The truth was, he didn't know what to make of their grunkles' situation. But he decided to follow the Mabel-like path and say "I'm sure they'll make up."

"Yeah... and I'm sure you're right." Mabel relaxed, and seeing this, Dipper got up and started toward his bed.

"Wait!" Mabel said suddenly.

Dipper turned back with a questioning look.

Mabel smiled and stuck out her arms. "Awkward sibling hug?"

Dipper couldn't help but smile back. "Anytime, sis."

Oof, I honestly feel kinda bad for writing this now, considering what happens 4 episodes later, but... maybe this just adds to why Mabel got so hurt in that episode? Yeah... I like that... It's a kind of twisted foreshadowing of things to come!

Anyway, hope you enjoyed. That flashback was really fun to write... now you know the (non-canonical, of course) origin of the awkward sibling hug!