Well, here is my second fic. With my first fic I had the beginning and end all planned out before I started posting it. However, I am embarrassed to admit that I don't really know how I'm going to end this one just yet. This being the case it is possible that updates may be sporadic till I find time in my life to make a solid plan for this fic.

Disclaimer: I don't own Gravity Falls; Disney does.

Hell, I can't even claim to own the idea of Reverse Falls: I think the concept originated from some mad genius on tumblr (at least that was the first place I encounter the idea).

Summary: In the original universe Grunkle Stan's twin brother, Stanley Pines, hid his journals so that 30 years later Dipper would find Journal #3. In this AU, Stanley decided to switch the hiding places of Journals 2 and 3. Who knew just that tiny change would cause Dipper to lose his mind? Reverse!Dipper Pinecest.

Title: Tolerating No Rivals

Chapter 1: The Amulet

Dipper knew the instant he saw that fish freak give his dear Mabel her first kiss that he was going to make it suffer greatly before allowing it the sweet release of death. Dipper felt his grip tighten around the amulet. He could feel its power begin to build within him. It was very tempting to fry the fish that dared defile sweet Mabel's lips immediately. That action would certainly impress upon Mabel that she had better pick rivals for him that were strong enough to contend with his power.

But, no: a quick death for Mermando, the fish freak, was a mercy that the freak did not deserve…and such action would cause undue distress to sweet, innocent Mabel. Dipper knew that bubbly girls did not like watching their boyfriends get murdered in front of them. He may not understand the sentiment in his heart, but he knew it with his brain. Dipper scowled as he forced his hand to relax.

No, not yet. Soon I'll strike down the entire merman species for the sins of this disgusting abomination before me. I'm going to boil the whole lake so that their entire damn city becomes their tomb. Mothers will throw their infants onto the shore in hopes some kind hearted fool will save them. Dipper felt an honest smile form on his face.

I guess I'll just have my faithful slave, the multi bear, patrol the lake. I might just order him to snack on a few of them. The thought of all those whores watching their little monstrosities get eaten as they themselves are boiled alive: it's just too delicious.

Then a thought stopped him: what if Mabel found out? Mabel could forgive a lot, but out right genocide?

No, my sweet, beautiful Mabel would not condone that. Even if they are subhuman filth. Dipper sighed. It was such a good plan too, but it would be much too easy to link it to me: most of the paranormal species of Gravity Falls know that the multi bear is my slave and of my magical powers. All it takes is one witness, and rumors of my slaughter would spread like wild fire. Word would eventually get back to Mabel. I need a more elegant plan. A war perhaps? Wars happen all the time. No one would know for certain it was me to cause it, though many of them would suspect. I could research the aquatic politics of the lake: turn a strong species against the mermen. Then in the ensuing war I could kill Mermando with my own two hands. The chaos of the war would cover my tracks. It's a start. I'll need the make a list and encrypt it when I get back home.

Dipper noted a deliriously happy Mabel approach him from the pier. He pasted a false smile on his face. Normally, Mabel would see through such ruse, but in her present state she was too happy to see the truth.

Oh, if only I were the cause of that happiness. If only I could taste the sweetness that is Mabel.

"Thanks for helping me rescue Mermando, broseph," Mabel gave Dipper an enthusiastic smile, "I realize you're risking your chance to spend all summer working with Wendy for Mermando's sake."

I didn't do it to help that freak. I did it to get that freak away from you. And I'm already spending plenty of time with Wendy at the Shack. Sure, the pool job really cemented my ploy to get everyone to think I'm crushing on her, but now the job has served its purpose. So there is no really loss even if Pool-check fires me. By this point everyone in Gravity Falls thinks I'm in love with Wendy. No one even suspects that I picked her because I knew she would never say 'yes' to a 12 year old. She is but a helpful smokescreen. Wendy may be beautiful, but she is not the subject of my desires. Not a soul knows of my true desire, and so it will remain till I find a way to get you to accept my love.

"Think nothing of it, sister dear," Dipper felt his smile thinned a little, but he kept it in place none the less "It was the right thing to do. I couldn't say no to you."

At least the last part was true. Dipper felt slimy for implying to dear Mabel that doing anything but killing Mermando was the 'right thing' to do. The only right thing to do to Mermando was burning the flesh from its bones as Dipper forced its thrice damned mother to watch.

Calm down, Dipper. Mabel may be distracted by the misplaced affection she feels for that damn fish, but even she would notice if you start raging in front of her. Even if that rage is justified, she would fail to understand.

"C'mon, if we hurry we might be able to return all this stuff before Pool-check arrives," Dipper said even though he knew Pool-check would already be at the pool waiting to rip him a new one. Like I care about a bunch of pool junk.

Pool-check's face turned bright red as he screamed at Dipper, "I leave you in charge of the pool for ONE night, and what do I find in the morning? ANARCHY! Complete and utter anarchy!"

Time to act like the Dipper everyone expects, "Please, give me another chance! I need this job…"

Crying would really complete the picture: think of Mabel's face when you almost cost her Waddles during the fair. The fair's plan was one of my more foolish ploys to convince everyone that I 'loved' Wendy. Ninety percent of that plan was wasted on time traveling, so the only one to truly be convinced was Mabel cause she was with me. All that effort to convince one person, I can be such an idiot.

Back to the point: think of Mabel's sad, sad eyes. They were so empty without Waddles. Utterly lacking the life that made Mabel, Mabel…and there it is.

Dipper felt tears prick his eyes, "What would I do if I don't have the pool job to spend time with…"

Dipper didn't have to finish: Pool-check knew. Everyone in Gravity Falls knew.

What complete and utter fools. The only thing I'll miss about the pool job is seeing Mabel in that cute, little, pink swimsuit. And even that was soured by being forced to what that little shit pretend to be all mysterious and flirt with her….breathe, Dipper, you're performance isn't over.

Pool-check's face softened, and for a second Dipper thought his manipulation was too effective—oh, no. He isn't really going to let me keep the job, is he? I mean look at all this: it's a disaster. The pool will be so boring now that Mabel has no reason to come.

Pool-check opened his mouth to speak, when Soos made his attempt to free the floaty ducks, and Pool-check almost popped a blood vessel.

And once again Soos unwittingly saves the day.

"Hand over your whistle, boy!" Pool check held out his hand, face hard.

Dipper pretended to give it up with regret. You can keep your dumb pool, you psychotic old man.

Pool-check popped the whistle into his mouth and started crewing, which was actually kind of hilarious, but Dipper did not allow himself the luxury of laughing. The Dipper everyone knows would not laugh after losing the chance to stare at Wendy's sexy red swimsuit all summer, so therefore I won't laugh.

Dipper kept his head down as he left the pool grounds. He had to pretend to be downcast at losing his job.

"Sup, doofus, you'll never guess what happened. I just got fired. Pool-check found out I was taking too many snacks," Wendy was awesome as always.

Dipper didn't have to pretend to be happy to hear that. Now I don't have to fake sulking for a day. Thanks again, Wendy. You know in another universe I could have easily fallen for you for real. You're gorgeous with an awesome personality. If that magical amulet didn't open my eyes to what I really wanted, if I never received its power: I might have spent all summer pining for you. But I did find journal number 2 near that fake tree, and within it was the location to my precious amulet.

At first I hesitated to use it, but when the gnomes tried to steal Mabel away from me, I had no choice. When I used its power to cripple the gnome leader and scatter the minions before me: I guess I found that power to be addicting. The first time I used the amulet, its power was overwhelming; it was intoxicating. And then Mabel pulled me into what she thought to be an awkward sibling hug. That hug pulled me higher than anything I've ever experienced. The amulet's power had heightened my senses. I could feel everything: the softness of Mabel's homemade sweater, and the softness of her budding curves underneath.

When the time came for our customary awkward double pat: I could not bring myself to do so. I only clutched her closer to me. I lacked self-control back then. I guess it was providence that I didn't know or understand the depth of my need for her or else I might have attempted a kiss.

As it was I only held the hug for 10 seconds too long: I could tell when I finally let the hug end that I had weirded her out: she couldn't meet my eyes. Her soft, brown eyes eluded my own. She had this adorable blush on her cheeks. It looked good on her, but she couldn't look at me. I knew I had to cover up my over reach; at least until I could find a way to make Mabel mine.

Which brought me to you, Wendy: you are perfect crush material. You are desirable, yet completely unattainable. I know that you will remain just beyond my reach for years to come. Most boys go through a phase of the 'unattainable crush,' so not a soul thought it odd when I started pretending to take an interest in you. And you've preformed perfectly: you've been friendly, while at the same time never reciprocating my apparent adoration. It is the perfect balance, so that I can continue to pine away. If you had not been friendly enough, people would wonder why I had not given up after a week. And if you had responded too positively, I might have accidentally found myself with an older girlfriend. Either way, my plans for dear, sweet Mabel would have been complicated. All I needed was a cover, and you, Wendy, are the perfect cover.

Dipper and Wendy continued chatting as they headed away from the pool, but Dipper's mind was elsewhere. It was one of the many gifts of the amulet: his ability to multitask had greatly improved. To every observer, Dipper appeared completely engaged in conversation with the laid-back girl; however, Dipper was also thinking about potential sources of information on the lake's aquatic politics.

My journal may have something on aquatic species—I just need to know which species is the most aggressive—but it probably won't include anything on the lake's alliance network. I guess I'll just pick the most aggressive species, and cast a covetous curse upon them using a black magic ritual. I wonder if there is a way to ensure that they'll target mermish territory. Perhaps a focusing array can be added into the original curse.

Dipper bid good bye to Wendy as they went their separate ways: Wendy was heading into town to hang out with her friends, and Dipper was going to the shack to get working on his just revenge. Honestly, Dipper couldn't even remember what they were taking about.

Mabel burst into her and Dipper's shared room an hour later, giddily clutching several bottles to her sweater clad chest, "Its official, Dipper! I am going to have a pen pal boyfriend for the rest of the summer. It's not as nice as having a real boyfriend, but, oh well, it's still totally romantic….what are you doing? Some nerd thing?"

She was half way through the speech before she noticed Dipper's….unusual morning activity. Before her laying on the ground was a huge poster board, and painted on said board was an extremely detailed and complicated magic circle. Dipper looked up from his magic journal and his work on a list which was probably written in some code or ancient language.

He started doing that code thing some weeks ago: shortly after he got that journal he obsesses over and that big gem he thinks I don't know about. Mabel hated that code language: her brotwin was keeping secrets from her and that just wasn't right. Twins were never supposed to keep secrets from each other. I don't know why he thinks he needs tah hide things from me: I'm his twin sister. Nothing will ever make me stop lovin' him: even if he is currently knee deep in black magic in the one city on earth where that stuff might work. Seriously, if a fundi Christian ever saw Dipper's little art project, they would tots think he was tryin' to speed dial Satan or something.

"Oh, hey Mabel," Dipper set his (probably cursed) pen down along with his encrypted list upon the night stand and stretched on his bed, "I just wanted to do some esoteric research on the ancient art of magic circles. You know: for academic purposes."

"Really, now? Cause it looks to me like you're actually trying to make a magic circle. What's it gonna do?" Mabel knew Dipper wouldn't give up the goods willingly. So when Dipper opened his mouth in what Mabel knew would be some stupid twin-secret-keeping denial, she pounced. Quite literally.

Mabel leapt on top of Dipper with an exclamation of excitement and straddled his hips holding his hands above his head, "No denying your nefarious plots, brother dear." Mabel added emphasis to addressing Dipper as a way of saying: yes, Dipper, I have noticed those small changes that are beginning to get quite weird. Especially, the 'sister dears.'

"Now tell me what the magic circle is for, or else," Mabel threatened with a cunning smirk on her face.

"You don't even know what 'nefarious' means; now, get off me, Mabel!" Dipper demanded, a nervous sweat was starting to form on his forehead, "You don't know what you are doing." This is such sweet torture, but it must end now or else Mabel is bound to notice…inappropriate reactions.

"Not until you tell me what the magic circle is for," Mabel's smirk thinned a little.

"Never!" I can't just tell her it is to precipitate the destruction of her boyfreak's species. Somehow I doubt she would be amused by that: even if it is hilarious.

"Oh, so you think you have a choice in the matter, brother dearest," Mabel knew she was in the driver seat in this conversation, "I guess I'll just have to show you why I'm 'boss Mabel.'"

Mabel released Dipper's arms, but before he could do anything to push her away, she jetted her hands down to Dipper's armpits and started wiggling her fingers back and forth, "Tickle, tickle, Dippingsauce!"

"What? No! Not that!" That was all Dipper could squeak out before the assault began.

"No-Hahaha! Stop—ha—it!" Dipper was choking on his laughter. One thing was certain: Dipper's enjoyment of Mabel's hips being pressed against him was greatly diminished.

"Tell me the truth!" Mabel repeated her demand.

"Fine!" At Dipper's acquiescence Mabel's hands stilled, but she kept her hands in place to renew her assault should Dipper change his mind, "It is to crush my enemies under the weight of their own despair! I will scatter them for the affront they have afforded me."

A look of utter surprise appeared on Mabel's face. Her hands which had been poised to start tickling again fell away from Dipper's sides as she sat back on her haunches (Dipper was so focused on Mabel's face, he was only partially aware of the position that Mabel's shift in weight had put them into).

"But…Dipper, you don't have any enemies. Least of all anyone who has 'affronted' you, whatever that is supposed to mean," Mabel was genuinely confused then an idea struck her, "You aren't going to really attack Robbie, are you? Robbie is a jerk. It's only a matter of time before Wendy realizes it. I don't think Robbie's worth the use of black magic of all things. Remember last time you used paranormal stuff to fight him. Rumble McSkirmish ended up turning on you."

"That was because I didn't understand Rumble's honor code," Honestly, who devotes his entire life to fighting 'bad guys' solely because they are bad guys? I tell a few, little lies to get Rumble to put Robbie in his place and Rumble finds out, and suddenly I'm the bad guy. Rumble was too much of a fearless meathead to be a good minion anyway. Rumble didn't understand that even if he beat me in single fish fight; I would inevitably win the war. The first thing I did upon losing in some lowbrow brawl was go to the arcade and fry the Fight Fighters arcade box. What's the point of having a minion that would dare defy me? Better to kill the impudent fool along with his entire universe than risk him defying myself a second time.

Dipper was speaking as he thought this, "On the other hand I know magic. I know it very well. There's no way for it to backfire on me. Magic doesn't have a will of its own: as long as one has sufficient knowledge on how to mold it, it will ever obey the caster."

A dark, intense look enter Dipper's eyes, "And I will not hesitate to use it to achieve my own ends, Mabel." Dipper continued to look into Mabel's beautiful, brown eyes, "Nothing will stop me from getting what I want, sister dear."

Mabel was made extraordinarily nervous by being on the receiving end of such a look, "Just be careful not to do something stupid, like raising the dead or something." Mabel shifted her weight nervously and it was at that moment that she and Dipper realized one very awkward detail: Dipper had definitely had that inappropriate reaction that he had been concerned about earlier.

Mabel flushed bright red and froze, "…Is that?"

"…Yeah," Dipper felt himself flush as well, but his embarrassment stemmed more from the fact that his usually ironclad self-control had been lost rather than actually regretting the position he and Mabel were in.

Dipper expected Mabel to leap off of him as if he had spontaneously combusted, but to his surprise she remained on top of him. Her flushed face was inscrutable to him, he could only guess what was going on behind her eyes.

Disgust, embarrassment, and something Mabel didn't have a name for warred in Mabel's heart. Her heart was hammering away. Oh gawd, this totally trumps the awkwardest moment of awkward sibling moments…and Dipper is still staring at me with the darkest eyes I have ever seen on him. What is that look in his eyes supposed to be?

Mabel was not one to ever be out matched so she stared back without even blinking. If it were even possible, Dipper's eyes got even darker. It was then that Mabel recognized the look in Dipper's eyes.

Desire. Holy crapnuggets. That is desire. Not even Mermando ever looked at me like that.

Then a second thought crossed Mabel's mind: why am I still on top of him?

Upon thinking this, Mabel's body finally reacted by leaping off of Dipper.

"Whelp, I'm gonna go read Mermando's letters," While in sweater-town. Yeah, time in sweater-town, while reading my boyfriend's letters will totally help me forget about—Nope, I'm not even gonna think it.

Mabel gathered up her bottles as fast as she could, and made to leave.

"See you around then, sister dear," Dipper tried to speak calmly, but there was a tremor in his voice.

"Bye, Dipper," and again Mabel couldn't meet his eyes.

Dipper turned back to his research. The moment on the bed had only hardened his resolve to torment and kill that damn mermaid.

After all, how dare it try to take my Mabel away from me. She is mine and I will not tolerate anyone or anything that tries to challenge me in that arena.

End note: And there you have it. Dipper is definitely not the same Dipper we all know and love.

This is a Dipper with power. One that isn't going to refrain from using it.

Here's the thing about crossing the line: once one has crossed it, there is no way to measure how far beyond it one has gone.

Dipper crossed the line weeks ago, and now he can't even till you in which direction the line is.

Will this be a story about Dipper's redemption or a story about Dipper's damnation? Not even the author knows the answer to that question (but it would be hilarious, if when Dipper reaches hell, he punches Satan in the face for daring to sit upon Dipper's throne [that was a joke]).