It's been years since Weirdmaggedon, Dipper and Mabel are 21 now, they still spend every summer in Gravity Falls with their Grunkles.
Mabel is studying at a major university and Dipper became Ford's assistant after he graduated early.
One summer morning as everyone was out having lunch at the Diner, Dipper decided to do some 'research' in Ford's lab since he now had free access to it. He finally had acquired some rare items he had been longing for, one of those were shackles which could keep any demonic energy locked turning any kind of demon pretty much useless, so he headed into the lab with a bag of items.
He picked out a small journal out of the bag and sat down on the floor drawing the zodiac, he spread something out of a bottle on the zodiac and chanted the words "Triangulum, entangulum. Veneforis dominus ventium. Veneforis venetisarium" After the incantation he threw the journal aside and waited.
"Bill? I don't have the whole day…" Dipper said annoyed as he sat up.
"But I do Pinetree" The demon grinned as he stepped out of the shadows this time with the form of a young slender man around his twenties, with unnatural yellow black hair and golden eyes, he was wearing a suit "I was having dinner in Paris… I hope there is a good reason for you summoning me" Bill said annoyed.
"You know summoning you with a body is a lot harder than just your ethereal form… I wouldn't waste so much time in gathering those ingredients if it wasn't important" Dipper exclaimed.
"Then what is it now?" Bill sighed as he neared Dipper, putting his arms around him.
"I need you to be my guinea pig with some new artefacts" Dipper uttered as he held up the bag smiling.
"Again? Can't you summon me for a cup of coffee… this is becoming a pain Pinetree" Bill exclaimed as he caressed Dipper's neck.
"The deal was I help you creating a body and you help me with such stuff once you have it" Dipper recalled… "And anyway you have been really touchy since you got a body… it is annoying"
"But its fun to mess with you" Bill grinned as he passed his hand over Dipper's crotch "Alright show me what you got this time… if they are fakes …" Bill threatened.
Dipper sighed a he pulled the things out of his bag, lastly the shackles he was so proud of.
"Hmm? The Cerberus Shackles?" Bill looked at them closely "Let's get over with this…" Bill said as he removed his jacket.
"You aren't even checking if they are real?" Dipper said surprised.
"I used to own a few of these myself, I know those are real when I see them" Bill remarked.
"Come on sit on the chair" Dipper demanded.
"Be careful kid I don't like being bossed around" Bill said as he obliged and sat down.
"Don't call me a kid, I'm twenty one now" Dipper replied as he tied Bill's arms behind the chair and lastly putting the shackles on him so he couldn't move.
"Only because you can drink now or what? You will always be a kid to me… Do we really have to go to this extend Pinetree?" Bill asked annoyed as he raised his eyebrow.
"Last time, you almost burned the Shack down… This is why we are trying these things here out and I'm making sure you can't destroy anything in a tantrum" Dipper explained.
"What now?" Bill asked annoyed.
"Dunno? Shouldn't those like restrict your power rendering you useless? Try to burn it down, break it, whatever I don't care" Dipper explained.
Bill tried breaking free, no matter what he did it didn't work.
"See real happy now?" Bill mocked.
"No…" Dipper smiled.
"Aha, then move to the next item, I don't have time for this" Bill urged.
"But I do" Dipper smirked "You have been an utter pain to me since you got that body" Dipper said as he neared Bill.
"Are you threatening me Pinetree?" Bill grinned.
"No, I just want a payback for things you've done to me" Dipper said as he took a chair and sat in front of Bill.
"You have to be more specific Pinetree I've done a lot of stuff" Bill grinned.
"Let's say this is payback for the snatching of my body… and you have been harassing me since you got a body…" Dipper explained.
"You can't mean the sock opera thing" Bill sighed "And the harassing part is one I can't deny, it's fun seeing you fluster over me touching you"
"The problem is Bill that you are not making me fluster..." Dipper said as he learned in to kiss Bill who couldn't move...
"What was that?" Bill asked annoyed as he blushed.
"You can blush?" Dipper smiled as he unbuttoned Bill's shirt.
"Stop now! Are you forgetting who I am?!" Bill hissed at Dipper.
"I know exactly who you are, you are the stupid demon who has been fucking with my feelings for the past years" Dipper said as he licked Bill's neck.
"And this is supposed to be payback…? Aahh" Bill let out a moan as Dipper bit his neck.
"You are awfully sensitive aren't you?" Dipper smiled as he kissed Bill again this time sliding his tongue into his mouth. As their tongues met Bill couldn't help but mimic Dipper's movements.
"You have never been touched before have you?" Dipper asked as he caressed Bill's chest.
"Do you really think I would willingly let a human touch me?" Bill raged.
"To me it seems like you are enjoying it" Dipper uttered as his passed his hand over Bills crotch, feeling his erection "I have barely touched you and look how hard you already are" he said as he traced Bill's chest with his tongue, licking and fondling with his nipples as he reached them, making Bill pant and whimper.
"I swear Pines I will make you regret shaming me like this" Bill raged as he was completely red.
"Tell me how does it feel... Having no control at all?" Dipper smiled as he opened Bill's pants, taking them off and leaving him with his unbuttoned shirt.
"Are you stupid Pines? I told you to stop!" Bill yelled.
"Like I would stop now" Dipper said as he caressed Bill's cock through his boxers slowly taking them of and starting to stroke Bill's cock, making him moan and pant at the Rhythm of his movements.
"Pinetree... Goodamit stop" Bill demanded once again flustered and panting in excitement.
Dipper only smiled as he licked his middle finger and started playing with Bill's entrance. Making him shriek as he inserted it.
"Why does it seem like you are enjoying it?" Dipper mocked Bill "A demon likes being taken by a human huh?" He increased the speed of the strokes as he fingered him at the same time.
"I don't… Pinetree... I'm going to... " Bill moaned as he came on Dipper's hand.
"Look at the mess you made and I barely even touched you..." Dipper smiled as he held his hand to Bill's mouth "Lick it" He demanded.
Bill didn't falter and started licking Dipper's hand taking his fingers into his mouth.
Dipper turned red as well since he wasn't expecting this reaction.
"More…" Bill uttered in a low voice.
"What..?" Dipper asked surprised.
"Goddammit Pinetree don't make me repeat myself... I said more... " Bill said as he blushed.
"You have no idea what you are doing to me right now... It was supposed to be payback and not you enjoying it... " Dipper sighed as he kissed Bill again.
"Unbind me... At least from the chair" Bill begged as he started getting hard again from Dipper's touch.
"Why would I do that?" Dipper asked suspicious.
"Please..." Bill begged in a lewd tone.
"Ugh... You have to do what I tell you... Otherwise back to the chair" Dipper explained as he searched his bag.
"I will... " Bill answered as he spread his legs.
"Shit... Bill where in hell did you learn that?" Dipper said as he covered his mouth.
Bill didn't answer he just looked away and let Dipper search through his bag, he pulled out a knife to cut the ropes Bill was tied with and a box.
"What is that?" Bill asked, still rock hard and longing for Dipper's touch.
"I bought this a while ago but never got to test it on someone" He smiled as he pulled out a vibrator and some lube.
"Pervert... Test that on someone else" Bill coughed.
"We will see who the pervert is..." Dipper replied as started with inserting two fingers again, making Bill moan. He put some lube on it and inserted the vibrator without warning making Bill shriek.
"It's not that big, you will get used to it" Dipper said as he turned it on sending a shiver through Bill's spine.
"Will you unbind me now?" Bill uttered again trying not to show how much he liked it.
Dipper sighed as he started cutting the ropes but, still leaving the shackles on Bill so his arms would be tied behind his back. Who of course cheated by passing them to the front so he would have more mobility.
"Sit on the chair Pinetree... " Bill demanded as he stood up still tied, rock hard and with the vibrator inside of him.
"What?" Dipper exclaimed confused.
"Please..." Bill whispered into Dipper's ear softly licking it before he backed up again. Dipper followed the instructions sitting down on the chair that Bill was sitting on.
He followed up and kneeled on the floor, opening Dipper's pants and sliding the zip down with his mouth, revealing the Dipper's hard cock under his boxers.
"You call me a pervert but, look how hard you are from just touching me" Bill grinned as he pulled down Dipper's boxers as well.
"Bill stop..." Dipper uttered as he blushed as well.
"You are not a Virgin Pinetree stop acting like one... Besides you started this" Bill said as he started licking the tip of Dipper's cock, slowly going to the shaft and back up… playing with the tip before taking it in his mouth… making Dipper pant... letting Bill suck him off since it felt too good.
After a while Dipper grabbed Bill by his hair, forcing his cock further into his mouth, making the movements faster thus making Bill choke on his cock.
"Hey a little respect over here!" Bill yelled as he tried to stand up.
"As if… Sit on my lap" Dipper said as he pulled Bill by then chains. Bill obliged and sat in a way that both their cocks would slightly rub against each other.
Dipper took both of them in one hand jerking them against each other... making Bill moan and slightly move his hips in excitement against Dipper's lap.
"I want to take you completely..." Dipper stated as he started biting Bill's neck, pinching his nipples with his free hand rather hard.
Bill let out a soft whimper as he was slightly pained.
"Did I hurt you?" Dipper asked surprised.
"I don't mind pain" Bill replied "I'm pretty sure I said that once"
"Yes, you were using my body" Dipper said annoyed "I remember that… if you like it so much then I won't hold back"
"You are holding back?" Bill asked confused.
Dipper stood up making Bill stand up as well with him, pushing him to the nearest table so he would rest with his chest on it.
"Trying to intimidate me Pinetree?" Bill smirked as he turned around and sat on the table.
"You are the one being cocky Bill…" Dipper said as he neared himself and slowly pulled out the vibrator, right afterwards inserting three fingers "Look at how loose you are" Dipper smiled as he fingered Bill.
"Take your shirt off" Bill demanded as he licked his own lips.
"Are you even in position to request?" Dipper chuckled as he took it off.
"Do you want it or not" Bill grinned as he spread his legs.
Dipper didn't answer as he removed his shirt… he moved closer to Bill positioning himself and slowly rubbing his dick against Bill's entrance.
"You said you didn't mind pain let's see how true that is" Dipper mocked Bill as he slowly inserted the tip making Bill let out a soft cry.
"Just hold onto me…" Dipper offered, Bill did as told embracing Dippers neck with his hands still in shackles, in that moment Dipper started thrusting into Bill making him moan in excitement even if he was in pain.
Dipper started panting as well as he left Bite marks all over Bill's body… still thrusting into him each time harder.
After a while Bill took his own cock into his hands stroking it at the pace of the thrusts, Dipper softly scratched Bill's back, leaving marks on him.
"Let me take you another way… or I won't last much longer" Dipper admitted.
Bill didn't answer he just lowered himself from the table and turning around, so that Dipper could take him standing from behind.
Dipper didn't wait as he started thrusting into Bill again, this time Dipper was the one stroking Bill's erection as he thrust into him quite hard, Bill whimpered in ecstasy making Dipper almost go crazy on how much he liked hearing Bill.
"Pinetree…" Bill started moving his hips against Dipper thrusts "I'm going to cum… again… slowdown" he said in a very lewd voice.
Dipper smiled as he started stroking Bill's cock faster.
"Pinetree… Stop… Ahhh" Bill moaned as he came on Dipper's hand and Dipper did inside of him.
They both panted as Dipper slowly pulled out and got something to clean up.
Dipper cleaned everything before he started getting dressed.
Bill sighed as he sat down on the chair.
"Let me get the key for those things... " Dipper said as he was done dressing.
"No need" Bill said as tore the shackles apart with force and snapped his fingers making him dressed again.
"You.. You tore the shackles apart?" Dipper said astonished.
"You really thought those things would keep me at bay? I'm not some low demon…" Bill said as he grinned and took Dipper by his collar "I think you truly are forgetting who I am Piiiinetreeee~"
"That means you could have gotten out... Whenever you wanted?" Dipper turned red.
"Yes" Bill replied as he put his jacket on.
"Then why didn't you?" Dipper asked confused.
"I guess you piqued my interest in a new way" Bill smirked as he kissed Dipper. "Next time call me like a normal person" He said as he handed Dipper a card with his number.
Dipper turned red at Bill's words "You were not supposed to like it!" he yelled.
"Too bad... You ain't getting rid of me any time soon" Bill smiled -´"Next time choose a nice place I've standards" Bill smirked as he snapped his fingers opening a rift.
"Wait..." Dipper stopped Bill from entering the rift.
"What is it now?" Bill sighed.
"Tomorrow evening?" Dipper asked.
"Sure" Bill smiled, with that Dipper pulled him in for a last kiss before Bill stepped into the rift.
"See you soon Pineeetree~"