"Okay, Buddy!" Billy's daddy said, 'I'll be back in a couple of hours. Be a good boy for Uncle Mark, alright?"

"O.K., Daddy," he cute 5 year old answered quietly.

"Take your time, Man," Mark said, laying a hand on the boy's shoulder, "We're gonna have a great time, aren't we, Sport?" he looked down at the adorable little blonde boy, who gazed back at him solemnly with his big blue eyes.

"Uh huh," he said noncommittally.

"Alright, I'll see you guys, then." Billy's daddy, Roger, said. He and Uncle Mark stood waving as his daddy drove away, then Uncle Mark directed him into the house.

"Come on in and get comfortable Billy," the man said. He took Billy's hand and led him into the living room. Billy entered the room first, and Mark followed. Billy looked around his uncle's house curiously. He stood still, waiting for his uncle to make the first move.

He didn't wait long.

"Come sit with me, Billy," Mark said behind him. When Billy turned around, Uncle Mark was naked. His semi-hard dick hung down between his thighs, six inches long and growing. Billy had seen it before. The first time had been a couple of weeks after Billy's daddy had forced him to suck his penis. Billy had liked it , and wanted to do it again. He had asked his daddy the next day if he could suck it, and he had sucked his daddy's cock almost every day since then.

His daddy had taken him to his Uncle Mark's house and Billy had asked Mark if he could suck his cock. Uncle Mark had been startled, and sat the boy down to find out why he had asked.

Mark wasn't surprised to find out that his brother had introduced the boy to oral sex. Roger was ten years older than Mark, and he had forced his younger brother to suck him off when they were boys. Mark, too had grown to like it, and sucked men off whenever the opportunity presented itself.

He had happily agreed to let the boy blow him, blasting a load in the kid's mouth after a few minutes of sucking.

Since then, Mark had watched Billy for his brother a few more times, and Billy had sucked him off every time.

Billy approached the couch where Uncle Mark sat with his legs spread wide and his eight inch cock exposed. The little boy wore a light blue baseball cap, which was tipped back to show off his light blonde bangs. Billy stopped between his uncles knees, and Mark reached out to pull the boy's t-shirt off over his head and push his shorts down his short legs and off. As usual, Roger had brought the boy over without underwear on. Mark replaced the cap, enjoying the look of the naked 5 year old, wearing nothing but the blue cap.

Mark lifted the naked 5 year old into his lap.

"How about a kiss?" he said, and Billy puckered up and pecked the man on the lips.

"I mean a real kiss, silly!" Mark said, and tipped his head as he leaned in to plant his lips on his nephew's mouth. Billy opened his lips and let his uncle's tongue slither into his mouth. The 5 year old put his skinny arms around Mark's neck and pulled his body against the adult man's. Mark turned the cap sideways, so the bill didn't interfere with his enjoyment of the child's mouth.

Mark reached behind his nephew and gripped his round ass cheeks in his hands. Billy wiggled his butt against his uncle's hands. The little boy loved having his body touched and fondled.

Mark was amazed at the boy's precociousness. The normally quiet, reserved kindergartener became voracious when it came to sex.

Billy moaned and squirmed in his uncle's arms as they kissed. Marc felt the boy's warm little hands slip between their bodies and reach for his erect cock. He moaned into Billy's mouth when the child's hands found his swollen member.

Mark took the boy's narrow shoulders in his hands and pushed him back.

"Today I'm gonna fuck you, okay?" he panted.

"Okay," Billy said. He had no idea what Uncle Mark meant. He only knew he wanted to suck the man's cock and swallow his cum. As long as Mark let him do that, the man could do anything he wanted.

"Okay, good." Mark said. He sat Billy on the couch and reached over to grab a tube of lubricant from a side table. He picked Billy up with his hands on his waist and set him on his bare feet in front of the couch. He turned the boy around and pushed him over with a hand between his shoulder blades. The boy bent at the waist, his firm round butt cheeks sticking out behind him. Mark gazed at the creamy globes of the little boy's ass and his cock pulsed. He massaged the 5 year old's butt cheeks, and Billy laid his head on the couch cushion and moaned softly.

Mark knelt directly behind his naked nephew with a hand on each pale ass cheek, pulling them apart to expose the tiny wrinkled hole nestled in the deep cleft between them. He stared at the little orifice, and his mouth watered.

Acting on impulse, the man bent at the waist and licked the boy's anus. Billy's head rose a couple of inches off the couch when he felt the odd sensation, and turned to see what his uncle was doing.

"Uncle Mark!" the boy gasped, "That feels great!"

Mark smiled at his nephew and returned his tongue to the little boy's asshole. He held Billy's hips in his hands and pressed his face against the warm ass in front of him. Mark pushed his tongue through the tight ring of muscle around Billy's anus, forcing spit into the tiny opening. Billy moaned and swung his ass back and forth, pressing back against his uncle's face. Mark was turned on. He knelt up behind the 5 year old and squeezed the tube of lubricant, collecting a glob of clear fluid on his fingers. He pressed his fingertip against Billy's spit-slicked anus, and the boy turned again to see what was touching him this time. He smiled up at his uncle and pressed backward until the tip of Mark's finger popped into his butt. He stopped and looked Mark in the eye, then pushed again, forcing more of the man's finger into his ass.

"You like that?" Mark asked as he pushed his finger deeper into Billy's hole.

"Uh huh," the boy grunted. His big blue eye closed and he smiled slightly as Marc continued to finger his anus. Mark spent several minutes sliding his finger in and out of Billy's asshole, until the opening had loosened to his satisfaction.

"Okay,"" he told the child, "Stand up, Baby Boy." He pulled up on Billy's hips and the child stood, bent at the waist. Mark moved closer, on his knees behind the little boy, and added lubricant to his cock. He coated the head liberally with the oily fluid, until it glistened in the lights of the room.

"I'm gonna stick my cock in your ass now, Baby," he whispered in the boy's ear "You ready?"

"Okay, Uncle Mark," the boy said innocently.

Mark put one hand on Billy's hip to steady him, and held his eight inch erection in the other. He rubbed the fat head of his cock against the boy's anus. Billy pushed backward encouragingly, and Mark took the hint, gripping the boy's slender hips and pulling his body back while pushing his own hips forward.

Billy hissed when he felt his uncle's big cock force his sphincter open. There was a flash of sharp pain, and he yelped, but then the cock head popped past the tight ring of muscle and was inside. Billy panted through the pain, and Mark held still to let the little boy get used to it.

When Billy settled down and his body relaxed, Mark leaned forward and wrapped his arms around the boy's body, pinning his arms against his sides in a big bear hug. Mark leaned against Billy's back, pressing the boy's small body against the couch cushion, and pushed his cock deeper inside his ass. Billy moaned, and his skinny body shuddered as his uncle fucked him, taking his anal virginity.

Mark stopped pushing after wedging four inches of his hot shaft in the child's anus, and started fucking him lowly.

Billy whined and panted, pushing back against his uncle's invading cock. Mark started pumping into his nephew's ass in earnest, holding his small, frail body to his chest tightly. He felt the heat of the child's back against his chest, and a layer of sweat made their bodies slide together as Mark fucked the 5 year old. Mark laid his cheek against Billy's head, feeling the fabric of the baseball cap against his face.

"Oh, Uncle Mark," Billy gasped, "Push it in me!"

"I'm fucking you!" Mark said, biting gently on the side of the little boy's neck.

"Fuck me, Uncle Mark!" the boy urged, "Fuck me!"

The lewd words, in the child's sweet, high-pitched voice, were too much for the man, and Mark came. He held Billy tighter, and jerked his spurting cock in short jabs into Billy's ass. The force of his jabbing thrusts knocked the boy's cap askew, which for some reason excited the man even more.

Billy squealed, feeling the hot jets of sperm against his rectum. He held still until Uncle Mark stopped jerking, and sighed when he felt the man's thick cock slide out of his stretched anus.

Billy felt wet warmth on his inner thighs as his uncle's semen gushed from his gaping asshole. Billy turned to look at his uncle, and Mark pulled him close for a kiss. Billy sucked Uncle Mark's tongue as Mark played with the boy's penis and felt his little sac between his legs.

Mark stood, and grabbed Billy's head in both of his hands. He pulled the boy's face toward his cock and slipped it into Billy's open mouth.

"Always clean off a cock after it cums in your ass, Billy," Mark told him. Billy sucked unenthusiastically on this uncle's cock, until he realized that it didn't taste much different than usual. He mostly tasted semen, which he liked, so he finished cleaning his uncle's cock eagerly.

- - - -

"So how was your visit with Uncle Mark?" Roger asked the boy on the way home.

"Good," Billy said.

They rode in silence for a while, then Billy spoke again.

"Daddy?" he asked.

"Yes, Buddy?"

"Can you fuck me when we get home?"

"Sure, baby boy," his daddy assured him, silently thanking his younger brother, "No problem!"