Dipper pulls the car over in the Mystery Shack's parking lot. Grunkle Stan and Stanley are waiting for them on the porch. Grunkle Stan is dressed for a lazy day – he's wearing a white tank top and boxer shorts tattered with hearts. Stanley, on the other hand, is sporting a black tee-shirt and a pair of jean-shorts. They smile and wave as Mabel and Dipper climb out of their car. Mabel runs to them laughing and shouting while Dipper makes a b-line for the trunk and gets their stuff. He's carrying as many bags as he can hold without dropping anything or tipping over.
Dipper greets his uncles the best he can. He sort of just nods at them and says hello before asking them to open the door. Now that he and Mabel are nineteen, they have their own rooms in the Mystery Shack. Mabel has taken over their childhood bedroom whereas Dipper has inherited Stanley's bedroom. Stanley sleeps in the basement where an additional room was built just for him. Dipper climbs the stairs to put Mabel's bags in her rooms before heading to his own. He doesn't understand why Mabel packs so much but shuffles it off to the fact that she's a girl – which he later thinks is a very sexist thought.
Dipper is expecting the same old wacky summers he always has in Gravity Falls. He knows evil gnomes, gargoyles, zombies and faeries are just around the corner and he can't wait to get back into the swing of things. He always loved hunting down new magical creatures and observing them – or stopping whatever shenanigans they were up to if they harmed humans in the process. However, Dipper soon realises this is going to be a very different summer in regards to all the other ones. He steps into his room just as Grunkle Stan, Stanley, and Mabel move to the kitchen. He hears them talking loudly and laughing and he knows they expect him to join them soon.
But then Dipper turns on the lights.
"Pine Tree!" Bill says in fake surprise, "Fancy seeing you here."
Dipper drops all of his bags.
There he is, in all his naked glory, lying on his stomach on Dipper's bed. Bill seems like he made himself at home – this is more evident when Dipper notices he managed to fish out the Journal from its hiding spot. The second he notices, Dipper's about to shout and reprimand him but then he remembers Bill is virtually powerless what with the events of seven years ago which, consequently, also resulted in Bill being trapped in a human body. A very sexy human body. One that Dipper had had fun with on multiple occasions.
"Bill…" Dipper says quietly and closes his door, glancing back and straining his ear to make sure no one's swinging by, "What are you doing here?"
"I came to surprise you!" Bill said and rolled onto his back, exposing his genitals, "And for sex. Lots and lots of it."
"Your timing is terrible. There are people here." Dipper groans and kicks his bags to the left side of his room to make space, "And why do you have my journal?"
"I got bored waiting for you." Bill says and promptly sits up, taking the journal in his hands. He then snaps his fingers and a pair of glasses pop on his face as such. Dipper thinks he looks particularly sexy with them on but pushes his lustful thoughts away. There are people in the house. "You know my eye sight is getting terrible? I pretended to be a normal meat bag and went to see one of your eye doctors; said I needed glasses."
"How did you get an appointment?" Dipper smirks, "You need to book ahead, let alone pay."
"I don't know if you've noticed, Pine Tree," Bill grins proudly and gestures himself, "But I got it going on."
Dipper's smirk drops to a frown. "You had sex with him in exchange for an appointment?" He says more than asks. He doesn't know why he feels bothered by this.
They're just sex-buddies.
"Bingo." Bill sneers, "As sharp as ever, I see."
"Well, whatever," Dipper says, "You have to leave. We can't have sex, especially when there are people here."
"But they're busy in the kitchen." Bill whines, "I got all naked just for you!"
Dipper blushes and bit but shakes his head. He has to concentrate. He has to remain strong. "They're literally expecting me to join them any second now." Dipper says, "If I take too long, they'll come find me and I really don't want them to find us together like this."
"Rude." Bill huffs. He then folds his arms over his chest stubbornly, "I want sex, Pine Tree!"
Dipper rolls his eyes as Bill begins to make a childish sound of frustration and anger. He stares at him, unimpressed, for a moment and, when the demon shows no sign of stopping, sighs in defeat. "Swing by tonight, when everyone's asleep." He says, "Only when everyone's asleep."
"Whoo!" Bill cheers, throwing his arms in the air.
"Oh, and Bill," Dipper adds quickly before the demon can teleport away, "Wear your glasses."
Bill blushes lightly at the demand. He nods and disappears a second later.
The night comes faster than anticipated. Dipper thinks it might be because of the beers Grunkle Stan forced upon he and Mabel. They all got pretty drunk fast and retired to bed early. Dipper is still awake because he's anxious for Bill to come back. He wonders if he'll be naked or if he'll be more reserved this time. Either way, Dipper doesn't matter. He expects they'll get down and dirty fairly fast.
Dipper falls onto his bed, lying and stretching before resting to stare at the ceiling. He can almost picture Bill and his naked body. He thinks it's sin for someone to look as gorgeous as the demon does – but then demons are the embodiments of sin, so he reckons it's adequate. And the more Dipper imagines Bill in his many forms of glory – smiling, laughing, moaning, cuming, among many other things – he begins to drift off to sleep.
He's almost asleep, having completely forgotten about needing to have sex with Bill, when the demon appears out of nowhere and falls onto his stomach. Dipper jolts awake and struggles to breathe for an instant, having been winded by Bill. Bill laughs loudly and rolls onto his back. When Dipper gets a hold of himself, he sees the demon is dressed but not as much as he thought. He's only wearing a long yellow sweater which just barely covers his butt and his dick. Dipper thinks it looks very cute on him but he's not going to say it because he's a bit miffed.
"You were going to fall asleep, shame on you!" Bill reproaches, "After you promised me to have sex!"
Dipper groans and shoves the demon off. Bill falls to the ground with an "oompf" and a thump. He quickly climbs back up and sits eagerly on Dipper's lap with a wide grin.
"You didn't even bring your glasses." Dipper grumbles.
Bill rolls his eyes and snaps his fingers. The pair of glasses suddenly appear on his face and Bill winks at him. "Boom!" he says.
Dipper smirks and licks his lips. He still feels a bit tipsy but this will in no way inhibit his capabilities. Or so he hopes. "Good." He purrs and leans closer, ready to pepper the demon's body with kisses.
Bill grins and grabs Dipper, pulling him over himself. Dipper presses his hands on either side of Bill's head and looks down at him. He looks so adorable with his blond hair sprawled around his head, his blushing cheeks, and his sexy glasses. Bill snakes his arm around Dipper's neck, bringing them chest to chest. Their faces are closer together and there's a moment of utter tension and Dipper's heart starts beating faster. For a moment, he thinks they're going to kiss but rather, Bill grinds upwards. Dipper groans and concentrates on what's what. This being said, he is still a bit disappointed.
Dipper leans his head down, angling himself to start necking Bill who's tilting his head to allow him better access. Bill begins moaning almost as immediately as Dipper's lips come in contact with his neck. At this point, Dipper knows exactly where all of Bill's sensitive spots can be found. He goes for them immediately, nibbling a bit roughly here and there but never drawing blood – he doesn't want Bill to get too loud what with the additional arousal of inflicted pain.
Bill quickly becomes restless and hopelessly bucks his hips against Dipper's. He wants more attention directed to his groin and Dipper is only too happy to comply. He reaches beneath Bill's long, yellow sweater and grasps his dick, pumping it as he left marks on the soft flesh of his neck. The demon's moans fill the room and augment in volume the closer he's getting to climaxing. Dipper doesn't notice immediately, it's just when Bill's about to cum that he stops – much to the latter's displeasure.
"What the fuck, Pine Tree!?" Bill snaps and tries to thrust into Dipper's hand, "I need this—you can't stop now!"
"You're too loud, Bill." Dipper says soundlessly, "You need to be quieter."
"How?" Bill asks impatiently.
"By not moaning so loudly?" Dipper suggests dumbly, "I don't know, if you absolutely can't control your mouth than cover it with your hand."
Bill frowns but nods. Dipper resumes his actions. It takes a bit before Bill gets back to the same level of intense pleasure nearing his climax. He's mainly gasping but here and there loud moans do escape his mouth. Dipper finds it impossibly hot to see Bill struggle so much. The demon ends up slapping his hand over his own mouth seconds before actually cumming and he ends up muffling what would otherwise have been a dangerously loud moan.
They breathe heavily – Bill out of exhaustion and Dipper out of arousal. Dipper wonders why he always makes Bill cum first. He reckons he should switch it up next time. In any case, he reaches next to his bed to where his backpack is sitting on the ground and pulls out a bottle of lube. He moved his bag there in anticipation. What Dipper had forgotten, however, were condoms. This being said, it didn't bother him that much because Bill cleaned everything to spotlessness when they finished fucking. He supposed the demon would do him the favour again.
Dipper opens the bottle and spreads a generous amount on three of his fingers. Bill ends up bringing both of his hands to his mouth in anticipation of the sounds that would undoubtedly follow. He spread his legs for Dipper. Dipper had to take a moment to appreciate the sight of Bill. Sometimes it was hard to believe the demon had once nearly destroyed all of humanity – especially when he's offering himself so prettily like this.
Dipper brings his first finger to Bill's puckered entrance. He circles it around the tense muscle, massaging it into relaxing before penetrating. Bill flinches and pinches his lips together, pressing the tip of his fingers against his mouth as he screws his eyes shut. It's evident he's trying very hard to keep quiet and it just adds to Dipper's arousal. Dipper slowly thrusts his finger in and out, spreading the lube as best as he can while encouraging Bill to relax to allow the easier transition to the second finger.
Bill starts moaning a lot when Dipper finally pushes in his second finger. His face is flushed with a blush and his hands are actually pressed hard against his mouth to muffle the sounds he's making. Dipper hates that he can't listen to Bill's gorgeous voice. He'll have to make up for it next time by making sure no one else is in the house so the demon can be as loud as possible. Dipper spreads his fingers apart, scissoring almost, as he continues to thrust his lube-covered fingers inside of Bill. Bill lets out a whine on accident and is quick to slap his hands over his mouth again. Dipper almost just wants to give up and let Bill be as loud as he needs to be.
Dipper likely would have if he didn't fear his family members bursting into his room, catching him in the act. Keeping Bill quiet is the best course of action to allow them to actually have sex without an interruption.
"P-Pine Tree—" Bill whines quietly, his voice trembling with lust.
"One more." Dipper says and pushes in his third and final finger.
Bill lets out a yelp followed by multiple muffled moans and cries of utter bliss. He quickly starts rocking back on the three digits, allowing them to penetrate him much deeper. The demon suddenly stiffens as his eyes widens, his body shakes, and gasps. Dipper grins to himself. He knows he's found Bill's prostate. He aims his three fingers at the general area he remembers it being and continues to probe it with varying degrees of intensity. Bill is mewling and shaking pathetically. His brow is furrowed in concentration to not start shouting in complete ecstasy – he nearly fails a couple of times but ultimately doesn't.
Dipper pulls out his fingers and immediately starts fiddling with his pants. He's been able to ignore the tight pressure on his groin for a while but now that he's getting ready to fuck Bill, it's getting unbearable. He unzips his pants and pushes them down just enough to pull out his throbbing cock while Bill pulls up his large sweater up to his chest. The sight of him in his glasses with his pink cheeks and exposed body nearly makes him cum then and there. However, by some divine force, Dipper resists.
He moves over Bill and probes the tip of his cock at his stretched entrance. Bill whines and looks up at Dipper from beneath the rim of his glasses with wide eyes. Dipper grins down at him and pushes the tip inside of him. Bill lets out a loud moan which is quickly cut off by Dipper's hand. Dipper hisses at him to shut up but the look in the demon's eye suggests that he's done making an effort. Dipper is thus going to be stuck keeping his mouth covered with his hand.
"You're such a child." Dipper condescends and pushes his cock further inside Bill.
He continues to push until he bottoms out. The two breathe heavily and, like all the other times, Bill's ready to get the show on the road far faster than Dipper is. He grinds his hips against Dipper's cock in a vain attempt to take him deeper. He rotates his hips desperately and begins keening to encourage Dipper to move and fuck him. Dipper, however, takes another extra moment to stare at him. He just can't believe how hot Bill is. He really loves the sight of him all wanton – especially with those glasses on his face.
"If you knew what you did to me…" Dipper sighs and pulls nearly all the way out before thrusting back in.
The first thrust hits Bill's prostate perfectly. The demon throws his head back, screaming a moan as he hopelessly clutches the bed covers beneath him. Dipper pulls out and pounds back in, abandoning himself to the primal need to have sex. He gets lost in the sensation of Bill's tightness, the muffled sounds and the slapping of their skin together. Everything's just so perfect and erotic. Sometimes he wishes he could just stay in this bed with Bill forever and fuck until the end of time.
However good things come to an end and this bout seems to have been much faster than the others. Dipper feels Bill tighten around him as his hips jerk wildly the way they always do when he's about to cum. Dipper wants to reach around with his free hand to jerk the demon off to completion but doing so would limit his thrusts. Bill, however, decides to take care of himself. He wraps both of his hands around his leaking prick and pumps furiously fast until he's screaming a muffled moan in Dipper's hand and cuming all over his chest.
The demon tightens significantly around Dipper's cock. He gets in a few more good thrusts before he too is cuming and collapses on top of Bill, the two of them breathing loudly, stuck in a mess of tangled limbs and cum. Dipper eventually pulls himself out, a large amount of spunk following his soften cock to freedom. Bill looks at it between his legs curiously.
"You filled me up nice." Bill comments and he means it completely innocently but it still does something for Dipper who enjoys sexy talk, "I can feel it inside me."
"Please stop talking, Bill." Dipper begs and lays next to him, on his side.
"You pervert." Bill smirks. He grabs his yellow sweater and stares at it in disappointment, "I really liked this thing. Now it's covered in sperm."
"Can't you clean it with magic or something?" Dipper yawns.
"I suppose." Bill sighs and falls back down onto the mattress. He cuddles close to Dipper and smirks, "So you liked seeing me all needy with these glasses, eh?"
"You're so chatty." Dipper mumbles and pulls the demon closer to his chest, "Just go to sleep or something."
Bill rests his head just beneath Dipper's chin, using his chest as a pillow. Dipper falls asleep as such, with Bill in his arms, and he wakes up the same way he does every other time: alone and clean. Though all the other times hadn't bothered him, Dipper admits to feeling a bit sad and lonely. He hopes he's not developing actual feelings for Bill. It could only end badly for him if he did.