Big Pines

Part 1

He may have saved the town, but he hardly felt like a hero.

Dipper Pines was making a return trip to Gravity Falls, along with his twin sister Mabel. While she had surely found something to do to spend her time here -- probably another summer romance or making friends with forest animals -- Dipper seemed less interested than usual.

Mabel was clearly growing up, her body developing all the things that would soon make her a woman. But Dipper didn't seem to see any changes in himself -- he didn't seem to be developing any "manly" traits in any noticeable way. He probably wasn't even that much taller from last year. Despite the fact he was on the verge of becoming a freshman in the fall, he still looked very much like a kid, at least in his eyes. And he still seemed to be striking out with Wendy. Despite going through so much together last summer, she still seemed to just be out of his league somehow. It seemed even Mabel was lapping him when it came to summer romances, again -- a few of her crushes seemed to be working out this summer.

While cleaning up at the Mystery Shack earlier in the day, Dipper found a comic book on the floor. It seemed someone dropped it while they were browsing the various freaky findings of the Shack's gift shop. Dipper planned on returning the comic book to whoever owned it, if they came back for it, but something about it struck his fancy. He couldn't explain it, but something inside him was attracting him to that comic book. Intrigued, he took the book upstairs to read. It didn't sound like any hero Dipper had heard of in passing, but the beefy, muscular hero caught his interest. Aside from the usual world-saving, he seemed to have everything one could want -- a physique to make even bodybuilders jealous, adoration and respect, and a beautiful girlfriend whose appearance reminded Dipper quite a bit of Wendy. And if the probably-inappropriate bulge was any indication, he'd surely have no problem impressing her elsewhere.

Dipper had been to health class for the first time over the past year, and about six weeks before he was set to head off for Gravity Falls again, he inadvertently began... discovering things about himself. He was relieved Mabel still didn't know about any of that. What would she even think, besides that her brother was starting to get gross?

But there was something about this hero's appearance that he couldn't stop looking at. His meaty, defined, sort of watermelon-y pecs, so protruding yet just chiseled enough to blur the line between female breasts and manly chest; big enough to cast a shadow on the chiseled, cut six-pack -- no, eight-pack, bordering on ten -- was that even possible? -- framed by two bulging arms that made those pecs feel right at home. By the time he wandered down to the strong, firm, trunk-like legs and... impressive package, he was too distracted to notice that his own package was looking to imitate.

Once the tenting in his shorts became too unbearable not to notice; Dipper became self-conscious, even though he was alone in the room, looking at the comic. In an attempt to clear his head, and quiet his other one, Dipper went out back and began to wander the nearby woods.

What is it that's making me so interested in that comic? Dipper thought. And why do I like that hero character so much? he continued, his stiffy softening as he walked. Last summer, the mysteries may have been in the journals, but now it seems there might be some mysteries inside myself I've gotta figure out...

After a while walking through the calming trees of Gravity Falls, the wind started picking up. Something beyond a breeze was forming; it was gusting. A shape seemed to be forming in front of him in the sky. It all seemed so familiar...

That couldn't be...? Dipper thought.

The form finally decided on its shape; a glowy yellow triangle with an eye in the middle of its front, as well as some appendages and a quaint top hat.

"Bill?!" Dipper said, completely shocked.
"Pine Tree?" The familiar floating isoceles responded, also somewhat surprised.
"But -- how -- I thought -- we defeated you!" Dipper uttered.
"Don't worry, kid, I'm not going to be back to that level of strength for another thousand years! You'll be ancient history!" Bill explained. "But for now, I need a little help from a lot of people to get there..."
"Forget it, Bill," Dipper stated firmly. "You may have fooled Great Uncle Ford, but I'd never help you."
"Foolish Pine Tree, you've already eliminated that possibility!"
"Huh?" Dipper asked, confused.
"You've already got a desire that I can 'help you out with'.
"What are you talking about?" Dipper queried, not following him.
"You've been taking a liking to a certain... comic book superhero?" Bill continued.
Dipper was both shocked and flustered. Now not only was he wondering how Bill came back, but also how he knew about that!

"I think you know thedeal, Pine Tree..." Bill said, offering out his hand, now ablaze with a blue flame. "How bad do you want it?"
"I'll never make a deal with you, Bill," Dipper insisted. "Not after everything you've done!"
"I knew you'd be hard to convince, Pine Tree..." Bill said as his other hand was set on fire in the same blue hue. "That's why I came with a backup plan!"
Bill thrust himself onto Dipper. The teenager tried to fight whatever Bill was attempting by trying to push him away, to push him off, but it was eventually futile, as Bill persisted and was eventually able to fight against Dipper's hands.

The triangle's blazing extremities were plastered to Dipper's chest -- seemingly stuck there, if only for a few moments. Then came a singing, burning sensation, as Bill's arms sank into Dipper's body. He was stunned by what he was seeing, but seemed paralyzed as to doing anything about it. He had never seen this behavior before. What was also startling was that while it felt like Bill's arms were charring their way through his insides, it seemed as if it had no perceptible effect on his body. No burn marks, no scarring, nothing. As if Bill were a ghost passing through or the moisture of a summer's rain seeping through his pores. Bill continued to push inward, Dipper somehow still feeling the force the triangular trickster was exerting on him, even though by this point his arms were nearly all the way in. As the main section of Bill's body sank into Dipper's chest, a flash of pale blue light seemed to blind and disorient him.

"Huh?" Dipper asked, after the flash, now seemingly alone once again in the wilderness. "Where did Bill go?"
"Surpriiise!"
Dipper shouted as he was caught off-guard. "You're in my head?! That can't be, that's impossible, that's -- "
"Not as tough as I thought it would be," Bill continued, his voice having a slight echo in Dipper's head.
"Get out of my head Bill!" Dipper urged.
"I don't think I can do that just yet, Pine Tree -- how else am I supposed to give you... what you want?" Bill triggered some of Dipper's deeper thoughts about the comic book hero from earlier.
"Agh! Fine, maybe I do want it, but not like this!" Dipper admitted.
"Don't worry, kid; in a few minutes, you won't even remember I'm here..."
"Stop messing with my head, Bill!" The urgency of Dipper's pleas was increasing as he feared what Bill was going to do to him, besides giving him 'what he wanted'. As Bill's effects started to kick in, and give Dipper an unexplainable headache, he tried to fight the interdimensional Dorito off, but his efforts were futile. As the inexplicable pain set in, all Dipper could do was let out a yell in the woods.


"Ahhhhhhhhhh!"


-

Dipper woke up in the forest, roughly where he was standing previously. He realized he had passed out, but he couldn't remember any reason why that would've happened. All he could think of was that he was feeling a little down due to his lack of personal successes this summer and went out for a walk in the woods to try and comprehend his thoughts about how hot that superhero in that comic book looked.

Wait a second -- Hot? That didn't sound right to Dipper. Did he like the hero in a romantic way? That didn't sound right either. He was pretty sure he wasn't attracted to the character like that, given he was still very attracted to Wendy. It was just that, when he looked at the guy...

His train of thought was interrupted. He felt a burning sensation develop across his chest. Dipper couldn't explain why it was happening or how it started. By all measures, he was alone in the woods. As he looked around for an explanation, the burning continued, and he felt his chest... thickening somewhat. It was the only way he could describe it. As he looked down at the fairly open neck of his shirt, he noticed his chest was protruding out a couple inches more than usual. In fact, it wasn't usual for it to be protruding outward at all. Puzzled, Dipper touched the new protrusions. Noticing their firmness, Dipper realized he was somehow growing a set of pectorals. As the realization came, it seemed hormones were starting to seep into his brain, as his touch became a feel, and almost a grope. Something about this just felt so good to him, so right. The rational, investigative Dipper Pines seemed to be falling out the window as the pecs grew further outward, almost as if they were responding to Dipper's sudden interest. They were becoming more and more visible against his orange shirt as the fabric was pulled upward and forward by the swelling mounds. As his chest stopped burning at what he thought was an already impressive size, Dipper felt the same feeling move down towards his stomach. He didn't eat anything spicy today, he thought, as his logical side briefly returned. The thickening feeling seemed to soon join the burning at the center of his stomach area. As Dipper looked down and lifted up his shirt, he could see the start of abs forming below his new pecs. Further intrigued, Dipper took a couple fingers and ran his hand up the growing muscles. The same feelings of hormones and lust began to trickle in again, as he shuddered from the pleasurable release. Did I just shudder? Dipper thought, parts of his mind still in conflict with the changes happening to his body. The feeling passed through his fingers and began traveling up his arm. Dipper watched in shock and amazement as the muscles in his arm began to swell. Dipper seemed to grow fixated on his rising bicep, flexing it as it grew in. Man, this does feel hot, Dipper thought. "Mmmm..." He touched his newly-enlarged arm as the growth spread past his neck, as traps rose from his shoulders and the neck itself thickened to match, revealing just a little of his Adam's apple. "Ohhh yeahhh..." Dipper continued, his voice deepening just a little to make him sound manlier, but not unfamiliar. His other arm soon swelled to match, and the sensation was sent down to his legs. Dipper's quads bloated outward to add to, then his calves expanded to help support, his new upper body weight, all while adding a little bit of height to Dipper in the process. Once his muscles had grown in, his body continued to expand slightly, figuring itself out somehow, until everything was perfectly in proportion. Before Dipper could really process what was happening, he felt the heat inside of him rise up and amplify as it met his crotch. Worried he was going to sweat down there, he opened his pants to see that his cock was expanding. Normally only a few inches soft, Dipper saw it grow beyond a size he ever thought was possible. Lowering his shorts and underwear further as it came down, Dipper seemed to feel his penis growing in the most out of everything on his body. Every moment, the shaft thickening, its length stretching further down, his balls growing as waves of added testosterone rush through his system. The bigger it grew, it seemed, the more Dipper wanted to use it. His meaty new member finally stopped at a length just before his knee, at a thickness a little smaller than a water bottle. While tempted, Dipper suppresses his now wildly increased urge to masturbate and instead decides to try and fit his dick back into his pants -- a somewhat harder task than before -- and have a look at himself. He looks down, admiring his bigger, sturdier legs, then after a few moments looks towards his right arm, raising it up and curling his bicep, watching it rise and fall. Amused with himself, and more than pleased with his new body, even though he didn't have an explanation as to how it happened or who to thank for it, he decided to finish up his walk through the woods. After adding a few more minutes to his stroll, smelling the fresh, Northwestern air, and feeling the wind on his buffed-up arms, he turned back around and headed back to the Mystery Shack.

However, before he could get there, he heard a familiar voice in the woods.
"Dipper? Dipper..."
While it sounded strange that Mabel would come looking for him -- and that fact made him question how long he was passed out -- his thoughts soon turned to worries about his new body. How exactly do you explain to your twin sister that you've gained an athlete's-envy physique in the middle of the forest in an afternoon? He started to take a detour, around the direct line that Mabel might be searching in, and around closer to the front of the Shack, in hopes of getting back inside without anyone seeing his new body. Once he began to see the side of the Shack through the trees, he started to slow down, maneuvering both for cover and to try and see if anyone was in the gift shop. After a few minutes, just as Dipper was getting ready to go in, he saw the door opening. Wendy emerged, looked around, and then went around to the other side of the Shack. Relieved, Dipper then decided to make his approach. Making a run for it, he dashed to the entrance, opened the door, and raced upstairs to the bedroom. Dipper sighed in relief, but wasn't tired at all -- and was surprised just how agile his new legs were. Feeling a little feisty, and also intrigued, Dipper fished out the superhero comic book he happened to find earlier and took it downstairs with him to the basement, or as Grunkle Stan would insist you call it, "The Hall of Mirrors".