Hermione Granger was in the Black Library reading. It was late at night during the summer holidays and she was staying over with Harry, the Weasleys, and the Order in Grimmauld Place. But she couldn't sleep since she was feeling horny. She was after all a growing teenage girl complete with hormones and a budding body. She had woken from a wet dream in which she was writhing in bed beneath an older man with curly black hair and dark eyes. She didn't know who he was and Hermione was particularly disturbed about that.

Sleep evaded her so she slipped into a thin silk nightgown that clung to her thin form and started browsing through the Black Library. At first she was surprised at how many naughty adult books there were in the library but then she remembered it was home to the womanizer and prankster Sirius Black, Member of the Marauders. As if on cue, Hermione heard a panting near her. Her head snapped up from her book and she looked in shock to see a large black dog sitting in front of her, panting and wagging his tale. Hermione blinked and remembered who it was.

"Padfoot!" Hermione squealed, and threw her arms around the dog.

The book dropped onto the floor and Hermione's gown slid upwards as the dog humped against her like dogs do when they are enjoying a good petting. Hermione sighed happily, glad that the friendly humorous wizard was back. He was off on Order business and the place was getting dull without his jokes and pranks. In fact, Hermione had a slight crush on the Marauder despite him being older than her being only sixteen years old.

"Shush," Hermione scolded gently. "You'll wake everyone up."

Padfoot whined and suddenly pushed Hermione over. Hermione yelped in surprise and fell flat on her back. She wasn't hurt but merely shocked and confused. Suddenly, the Animagus climbed on top of Hermione and started licking her face. Hermione burst into giggles and started trying to push Padfoot away though she was secretly enjoying the romp. The dog would not move, however, and Hermione started getting worried as the dog got friskier. Her suspicions were confirmed when she felt something hard and long press into her stomach.

"Oh my!" Hermione gasped.

She stiffened, wrapping her arms around Padfoot and leaning against the chair. He whimpered and unconsciously started humping her belly causing Hermione to moan. The bushy-haired witch buried her face in the animal's hair and rubbed his fur hoping to distract the dog.

"Stop, Padfoot," Hermione whispered fiercely. "It feels good but you should stop. If someone finds out we will get in trouble. You could go to prison."

Padfoot growled quietly as if threatening to rip apart anyone who would separate them. The thought caused Hermione to feel warm and safe but she was still worried; also due to the fact that a horny dog was humping her!

"Please, Paddy," Hermione begged. "Get off me. Come on, Sirius. I know you're in there."

Padfoot growled warningly and continued to hump her, picking up the pace. He began slobbering with his wet tongue all over Hermione's small breasts. Hermione moaned feverishly caught off-guard at how good it felt. The Grimm tore at Hermione's gown careful not to scratch the girl and started lapping up at the bare creamy flesh.

Hermione nearly cried out in pleasure but clamped her mouth shut. Groping for her wand, she cast some privacy spells with shaky hands so no one would see or hear them for a short time. She also managed to cast a contraceptive charm before her wand fell out of her hand and she shrieked in pleasure.

"Morgana's tits!" Hermione shrieked.

She was now drenched in sweat and Padfoot was humping her brutally. She would have a bruise on her stomach for sure. Trembling and flustered, Hermione carefully grabbed Padfoot's stiff member and guided it into her pussy. She braced herself for the pain and screamed in agony as Padfoot penetrated her.

The Animagus howled in triumph as he claimed his mate and started pounding her tight hot pussy wildly. Wet squishing sounds, panting, and slapping filled the room and Hermione sobbed as she tried to ignore the pain. She hooked her legs around Padfoot and wrapped her arms around him, clinging desperately to him.

Her body clenched and shook as she was thrust into by the large black dog. Finally, just as the pain was about to subside; Hermione felt Padfoot get larger and larger. Padfoot came, unleashing torrents of thick cum. Hermione sighed in relief and collapsed on the ground. Padfoot whimpered and writhed and stretched, transforming into a nude limp Sirius Black.

The Marauder was covered in sweat and limp. He lay still on Hermione, his face buried in her small breasts. Hermione smiled tiredly, playing with Sirius's hair.

"That was unexpected," She said at length.

"But appreciated?" Sirius asked hopefully. "I tried to stop myself but Padfoot took over. You are too hot for your own good, you know."

"Ever the womanizer," Hermione smirked. "Don't worry. I won't tell anyone. So long as you shag me again and again and again. And only me!"

"Only you," Sirius grinned, looking up at Hermione. "But if you want another fuck I will have to get hard again."

"Come here you," Hermione grinned and pulled Sirius into a kiss.

Their first snog was awkward and wet and not at all how she expected but felt very good. Hermione moaned and felt herself get wet. Sirius pulled back and grinned, slipping a finger in her crack. He stroked it softly and suckled on Hermione's breasts. Hermione moaned and stroked Sirius's back and arms, gripping his tight bum.

Sirius began stroking Hermione harder and faster, eventually inserting a second finger in her. Hermione began shaking and crying out in pleasure. Sirius worked faster and fiercer. Hermione tensed and then squirted cum all over Sirius's hand and arms. She gasped, trembling from the orgasm. It was her first one ever.

"That was fucking awesome," Hermione groaned. "Let me repay the favor."

Breathing deeply, she flipped Sirius over so he lay on his back and began stroking the older wizard. Sirius moaned and sat up, fondling Hermione's nipples and breasts. He slid a hand down her back, groping at her bum and slipped a finger inside her rear end.

Hermione moaned and jerked Sirius harder. Sirius groaned and pushed her head downwards gently. Hermione obeyed and kissed Sirius's cock. Sirius's penis grew harder as Hermione lowered her lips on it. She was an amateur but Sirius enjoyed it all the same. Hermione soon picked up the speed and started sucking deep and fast.

Sirius fingered Hermione's arse, fucking her with his finger. He pushed a second finger into Hermione's bum causing the young girl to stiffen but then relax as pleasure overtook her. Soon Sirius was raging hard but he slipped out of Hermione's mouth and pushed her against the floor.

His eyes glazed with passion as he kissed the young Gryffindor and lowered himself onto her pussy. He paused before thrusting into her causing Hermione to cry out in pleasure. This time it felt much better and Hermione cried out for Sirius to fuck her harder. Sirius obeyed gladly and the two made love long into the wee hours of the morning.

Sadly, they had to stop and go to their own rooms before everyone woke so they did so hastily, quickly cleaning up the mess of cum and sweat and ripped clothing, and dog hair. Needless to say, Hermione Granger and Sirius Black became boyfriend and girlfriend despite having a secret relationship.

Eventually, Hermione turned seventeen and was an adult witch. Because of their love for each other, Sirius didn't die from the Veil since he was trying to keep Hermione safe in the Ministry. When Hermione came of age, she revealed her relationship with Sirius to everyone though they said they only got together on Hermione's seventeenth birthday.

After the war, Sirius Black was pardoned and declared a National Hero along with Hermione, Harry, Ron and the others at Hogwarts and the Order. Hermione and Sirius got married and moved into Grimmauld Place where they lived together happily for the rest of the days; and having lots of hot sex as both humans and Animagus.

THE END!