Dipper was staying in a hotel with Mabel, both had just turned 18. They were on the outskirts of Gravity Falls, it took a while to drive there and they had started the trip later in the day and needed to rest.

Mabel had been the last to drive while Dipper slept. When they arrived in their room she promptly face planted onto her bed after carelessly dropping her sticker covered suit case.

Dipper on the other hand had been quite awake, and went to go to the pool that the hotel had open 24/7 with no lifeguard. He hopped maybe swimming a few laps would help tire him out and the cold water would distract his mind from turning to thoughts of a certain triangular, recently human, demon.

Dipper dropped his towel on a chair and cannon balled into the deep side of the empty pool. He stayed under for a while, his hair floating around his eyes, and the white laces his red trunks float upward. After taking it all in and relaxing Dipper shot towards the surface and took a long deep breath.

"Careful Pinetree, I've learned humans dont do to well under water."

Dipper gasped at the humanized familiar voice. His grunkles had sent them letters over the school year to keep them in the loop. Ford had written telling them that in order to try and avoid future chaos that they had turned Bill human.

As Dipper turned to try and get a look at the new Bill he stopped at a 60 degree turn to find a golden blonde man standing in the pool directly in front of him.

The man had a strong jawline and black coal eyes. His freckled shoulders lead to a slender and tattooed body, covered only by brown swim trunks.

"Hey kid, my eyes are up here." Bill said.

Dipper blinked out of whatever trance he was in. He looked back up and stared Bill in the eyes. He looked about a year older than Dipper.

"You look pretty out of it kiddo, you okay?"

Bill asked while wearing a concerned look. Dipper just stared at him and nodded slightly.

"Why are you here?" Dipper asked in a soft quite voice.

Bill looked down at the blue tinted water and a little above a whisper said,

"I wanted to see you Pinetree."

Dipper was taken aback. Bill missed me? Dipper thought to himself. He grinned at the thought. He missed me.

Dipper then stood on his tippy toes and wrapped his arms around Bills neck, and nuzzled his face into the crook of his neck.

"I missed you too." Dipper whispered into Bills shoulder.

Bill wore a small genuine smile on his face, after getting over the surprise.
Bill leaned into the hug and wrapped his arms around Dipper's waist and let his head droop to where it was resting on Dipper's shoulder.

Dipper pulled away after a while and stood there. He had his hands resting on Bill's shoulders and Bill had his hands on Dipper's hips.

The water was calm except for the splashing sound from it hitting the filter. The only outside noise was the occasional car passing and a cricket or frog in the background. The moon was glowing a brilliant white and the stars looked amazing.

Dipper knew it would be a terrible idea,  but he had to do it.

Dipper leaned in again, but this time it wasn't for a hug. Dipper hooked his hands back around Bill's neck and kissed him. It was sweet and short and quite overdue.

Immediately afterwards Dipper leaped backwards, starring down at the water.

"Um, uh, I-I'm sorr-sorry, I-I just had t-to test something." Dipper stuttered trying to avoid eye contact.

Bill was frozen. Pinetree kissed me. He thought. I have been kissed by Dipper, and I froze.

Dipper looked up at Bill, expecting to be yelled at, or for him to have vanished. He was surprised at what he found. Bill was still there. He has a surprised look plastered on his face and his eyes held a starstruck look to them, his mouth was open slightly and looked as soft as it felt.

Dippers eyebrows knitted together in a concerned look. Dipper reached out to try and rehabilitate Bill when he blinked a few times, then Bill's eyes jumped to Dipper, staring right into him.

Bill moved forward and put on hand on the small of Dipper's back and the other under his arm under the center of his shoulder blades. Bill pulled Dipper close to him a kissed him. It was gentle but longer and more passionate than last time.

Dipper moved his arms around Bill's neck and tangled his fingers in his dripping hair. Bill felt Dipper wrap his legs around his waist as he swiped his tongue across Bill's lower lip, asking for entrance.

Bill open his mouth eagerly and let Dipper take the lead. The kiss got hungrier when Dipper pulled away, panting and gasping for air. There was a trail of spit connecting their mouths from how wet the kiss had got.

"Can we take this somewhere else," Dipper asked quietly with hope filling his voice.

Dipper pupils were blown with lust and need. Bill quickly whispered,

"I have a room."

Dipper didnt question it, he just needed Bill. Once Bill had transferred them into an empty room he carried Dipper over to the bed while making a swishing motion with his hands. Dipper heard the door lock as Bill set him on the bed.

Dipper was sitting on the edge of the bed, the room illuminated by the moonlight coming in from the transparent blinds. Bill was sitting in between Dipper's legs, his arms next to Dipper's hips.

"You sure Pinetree?" Bill asked.

Dipper shook his head up and down for a yes, wanting Bill to hurry.

Bill trailed his fingers down Dipper's chest and abdomen. He worked them around the waist band of his swim trunks, ghosting over the skin causing Dipper to shiver with anticipation. Bill started untying the knot of laces that held up the trunks and carefully slid his hands across Dipper's thighs to the end of the swim attire.

Bill pulled the trunks down carefully and slid them down Dipper's legs and to the floor. Bill lent forward and wrapped his arms around Dipper's  lower back, and reached up to kiss him. Dipper's  hands found their way to Bill's head and tangled themselves in his hair.

Bill started kissing down along Dipper's  jawline and down his neck. Bill stopped once to leave a hickey behind Dipper's  ear. He sucked and licked, causing Dipper to moan, which drove Bill crazy, Dipper moaned again when he felt Bill's  teeth graze against the forming bruise.

Bill kissed and made his way down to Dipper's hip bone. He looked up at Dipper, who's eyes were closed with his head tilted back. Bill smiled at his reactions. Bill looked down at Dipper's formed erection. Bill kissed along Dipper's hipbone and down his upper thigh.

Bill went to the soft skin of Dipper's inner thigh and started sucking. Dipper moaned and his boner twitched in excitement. Bill licked around the freshly purpled skin and listened to Dipper panting.

Bill moved his hand under one of Dipper's thighs and lifted it onto his shoulder. Bills other hand trailed up and down Dipper's other thigh. Dipper squrimed and groaned. Bill had the realization that Dipper could come apart in his hands if he kept this up.

Bill lowered his head down and ghosted his tongue over Dipper's head. Dipper squrimed a little as Bill's hot breath hit his member. Bill loved the way Dipper moved and moaned, his reactions. They were beautiful.

Bill reached one arm under his thigh and wrapped it up to Dipper's ass. Bill squeezed a cheek as Dipper  jumped. Bill had moved his hand to where Dipper was basically sitting on it. Dipper moaned as Bill set a light kiss on his stomach and started palming him.

Dipper half gasped half moaned when he felt Bill wrapped his hand around his shaft and rubbed his thumb over his tip and around his head.

Bill suddenly removed his hand from Dipper's member and lowered his mouth to it. Bill wrapped his lips around Dipper's head and swirled his tongue around the slit. He stuck his tongue in the slit slightly and heard Dipper moan something ineligible and felt his hands tremble and yank softly on his hair.

Dipper moaned and felt a tremble shudder through him as Bill's teeth ghosted across the sensitive skin on his member. Bill took Dipper in fully and started bobbing his head up and down. Dipper was quickly reaching his climax and Bill knew it.

Bill removed his mouth from dippers member, Dipper's eyes had rolled back in his head slightly when Bill pulled Dipper closer. Bill came up and kissed Dipper roughly. Bill tugged Dipper's lower lip and sucked on his lips slightly till they were swollen.

Bill tugged on Dipper's earlobe and returned to his previous hickey on Dipper's inner thigh. Bill left three more hickeys on Dipper's thigh before ghosting a finger over Dipper's slit causing for him to moan.

Bill quickly grabbed Dipper's  member and started jerking him off. Dipper's fingers tugged at Bill's hair as he moaned and gasped for air, which had apparently left his lungs temporarily.

After a few of timed jerks Dipper came in spurts. The white liquid covering Bill's hand and dripping form his fingers.

Dipper fell back on the bed exhausted while Bill went and changed into boxers. Bill washed his hand in the bathroom sink before kissing Dipper's on the head.
"See ya in Gravity Falls kid, I can't  wait."