Marty stumbled down the road, barely keeping himself upright. The party had been wild. The Hill Valley Sharks had just won their first game of the season against their rivals and where there is a win, there is booze. Holy shit was their booze. His head swam from the tequila shooters, rum and Pepsis, and of course, the beer. "Oh God, shouldn't have done that keg... stand." He left the party around eleven and after falling off his skateboard several times had decided to walk home.

Halfway home, his alcohol-addled mind registered that the house of his friend and mentor, Dr. Emmett Brown. Truth, be told, he trusted that man more than his father. He also knew that Doc would not bat an eyelash at his drunken state, Doc being quite the wild one himself. He tripped up the short steps to Doc's door, essentially knocking on the door with his face and cutting a nice gash across his brow.

Dr. Emmet Brown was startled by a loud knock on his door. "Damn police again." He rolled out from under his latest invention and stormed out to the door. Poking his head outside he exclaimed: "I TOLD YOU! I HAVE THE PROPER PERMITS FOR MY-" He saw no police. His brows crinkled in confusion as he scanned his front yard. As the scientist turned to reenter his house he heard a groan from the ground. "GREAT SCOTT! Marty! What's happened to you boy?"

"I wasah walkand then stepsssss fell oversshhhanddd."

"Good Lord what have you been drinking?" he said as he sniffed Marty's breath. "Hmm, good stuff, apparently." He hefted Marty's diminutive frame in his muscular arms and brought him inside. After laying him on the couch, he left for his medical kit. Marty's mind was swimming from the fall and the booze. His thoughts wandered back to the party.

"Jennifer." He whispered. They had gone to the party together and after a couple of drinks retired to a bedroom on the second floor. They had been making out for hours, him rubbing her through her panties, she stroking his cock through his jeans. He lost himself in the recent memory, an erection growing in his pants. She slowly undid his zipper under the blanket. His mind was doing backflips. She pushed her body closer against his. Her hand slinked into his pants, resting lightly on his boxers. He felt his boner strain against the fabric. She felt it jerk and smiled at him, slid her hand into his underwear. He nearly blacked out as she gripped him. She made a small groan in the back of her throat, that nearly drove him over the edge. The world could end right there and he'd have been happy. She quickly moved her hand up and down his shaft. He wasn't going to last long. She sensed this and quickly removed her hand. "What the fuck?" She sat up, a smirk on her face mocking him. He came up to meet her, and silenced the smirk with a kiss. His tongue brushed her lips and they parted. Their tongues met in a heated swirl. She tasted amazing. She grabbed the back of his head with one hand, yanking him closer by the hair to deepen the kiss. He placed his on the small of her back. He felt her other hand on his stomach. She broke the kiss.

"You've got a bit of a six pack skinny boy."

" Shut up."

Her nails dug scratches in his stomach as she lowered her hand once again to his crotch. This time she dropped his pants from his hips and began to pump him without leaving the kiss. He knew if she continued like this, he wasn't going to last much longer. So he took the initiative. He leaned into her and she toppled onto her back at the foot of the bed. He on top of her, she looked up, guessing at his intentions, which became clear as he lowered his head, first kissing her neck, breasts, down to her belly button, he looked up. Was he asking for permission? If so, she gave it. She unbuttoned her pants, which he quickly pulled off, leaving purple underwear.

Doc felt true fear as he ran for the first aid kit. He cared for Marty more for anyone in the world. He was the only reason he kept on with his life. Well, Marty, science, and Einstein of course. But Marty was truly the center of his life. His knees nearly buckled when he returned to Marty, the blood was pouring out of the gash in his head. Despite this, Marty's seemed…. slightly pleased?

He knelt next to Marty, bringing his face within inches of the boy's. His eyes were not what they once were and the medical work required accuracy. He leant in to apply antibiotics.

Marty was still lost in dreamworld. "Jennifer."

"Jennifer?" Doc replied as he dabbed the young man's forehead with peroxide.

"Jennifer!" Marty exclaimed, eyes still shut, still in his fantasy, grabbed Doc's face and pulled him in for a kiss. Doc was dumbfounded. The boy pulled the man's towering frame onto his own. Marty grabbed the back of Doc's head, tangling his fingers in Doc's white mane. Their tongues intertwined. Doc was lost in the moment, not comprehending, just feeling the young boy's touch and tasting his tongue. The realization of what was happening hit Doc like a locomotive. He pulled his hands from where they were pinned under him and pushed himself off of Marty. Marty's eyes shot open. He gasped. He saw Doc sprawled on the floor next to the couch and connected the dots. He had just gotten to first base with his long time friend and mentor, Doc Brown. And he liked it. Fuck Jennifer. I've come to this point and I cant go back. Doc felt pure fear as he saw Marty stare at him. That is, until he saw the smirk cross the kid's face. He didn't want to admit to himself how many times he had fantasized about this. He thought of speaking but words would only ruin the moment.

Marty rolled off the couch and slunk towards Doc, who was lying on his back, propped up on his elbows. He crawled on top of the doctor and hovered his face inches away from the old man's. Doc was old, but his body was strong and lean from years of adventure. He sat up so Marty was sitting on his lap, Marty's legs wrapped around Doc. Their mouths collided in a storm of passion. Marty found that Doc was actually biting as he kissed him. He nearly cried out but he found he became more aroused the deeper he bit. From his position he could feel Doc's rock hard cock growing beneath his ass. He began to grind on Doc's lap, causing the man to groan. Suddenly Doc stood up, holding Marty in his arms. He rushed to the lab and threw Marty down next to a wall crossed with electrical wires. He began to strip as if his clothes were aflame. Marty did the same. Marty gawked at the size of Doc's dick. He would have felt a great deal of penis envy if he didn't know what he was about to do with it.

Doc quickly unplugged four thin, long, black wires from the wall. He pushed on Marty's shoulder, Forcing him to his knees. He tied the wires around the boy's wrists and ankles so each wire was wrapped around each limb, pulling Marty's arms apart and spreading his legs. Marty leaned forward into his restraints, eager to taste Doc Brown's raging erection. Doc was more than willing to oblige. He dug his fingers into Marty's brown locks as he began. He kissed the tip, then slowly licked down the shaft, eliciting a groan from the older man. He licked back up his length and ended by swirling his tongue around the head. This was more than Doc could bear. He forced Marty's head down on his dick. Marty nearly gagged as Doc's full ten inches were shoved down his throat. With and effort, he began to bob his head. He had a raging erection himself and began to grind it against the carpet. He heard Doc groan a second time and quickened his pace, continually moving from base to tip, swallowing the entire length each time. Doc gave a final grunt and what seemed like gallons of cum poured down his throat. He had no choice but to swallow. He did what he could but some still filled his mouth and poured down his chin. Doc wasted no time flipping Marty around and repositioning the wires so he was spread exactly like before, but facing away from Doc.

Doc knelt and placed his throbbing cock at Marty's pink entrance. Marty strained backwards toward Emmett's member but Doc withheld. "Say you want it."

"I wanna itsshshaa." Still drunk. He ground his ass against Doc.

"Good enough." Doc moaned as he sunk himself to the hilt in Marty. Marty screamed in pain, but with each successive pump the pain subsided and the uncontrollable, animal pleasure rose. Doc reached under Marty and grasped at the Boy's cock. Marty sighed with pleasure. Doc began pumping Marty's dick with his hand as he fucked his ass. He could not believe what he was doing. Illegal? Maybe. Unethical? Certainly. But he couldn't care. All that mattered now was the rising force of lust within him. He grasped Marty's shoulders and pulled up, breaking the plugs from the wall. Doc pulled Marty's back to his chest and pulled him to a standing position, throwing him against the wall. Taking hold of Marty's cock again, he resumed the fuck. The sight of his dick pumping in and out of Marty's young, pale ass drew him into a climax. Marty began to come as well In Doc's hand. His cum shot out in three white ropes onto the carpet. Doc thrust his dick as far as possible into Marty's ass and shot his load.

Heavy breathing and sweat, they fell into an embrace. Doc pulled a blanket over them two and they slept the night, not caring what chaos the morning would bring. They had each other