Disclaimer: I don't own any characters or concepts; they belong to their respective owners.
Note: All characters are written as older than 18 years of age.
Fred and George cornered Harry as he walked dejectedly away from the Entrance Hall. He had just seen Ron and Hermione off to Hogsmeade yet again, and was despondent that he still wasn't allowed to go. The twins walked beside him, striking up a conversation.
"Not going to Hogsmeade today?" Fred asked.
"No", Harry replied unhappily. "McGonagall won't let me because my aunt and uncle didn't sign my form."
"We've never let something like forms stop us", George commented.
"Yeah, well I don't know all the secret ways out of the castle", Harry said.
Fred and George gave each other knowing looks around Harry. They steered him into an empty classroom, and shut the door behind them. Fred took a crumpled piece of parchment out of his pocket, and spread it out on a desk. He looked proud of it. Curious, Harry leant over the desk, trying to see what Fred and George were showing him. The parchment, though, was blank. Harry sighed.
"I'm not in the mood for pranks", he said.
The twins smiled mischievously.
"Since when have we pulled pranks?" Fred asked, with mock offence.
"We're as true and honest as can be!" George added.
They grinned at Harry.
"This", George said, pointing at the parchment, "is the secret to our success."
"You can write yourself wherever you want?" Harry guessed.
"Better", George said.
Fred pointed his wand at the parchment.
"I solemnly swear that I am up to no good", he intoned.
Immediately, ink appeared on the parchment. Soon, Harry saw a detailed map of Hogwarts drawn out in front of him.
"What is it?" he asked in a whisper.
"The Marauders' Map", Fred said proudly. "It shows all the passageways in the castle — including all the secret ones. You can also see where everyone is in the castle."
"It's our greatest treasure", George added.
"And we're giving it to you", Fred concluded.
"What?" Harry said, tearing his eyes away from the small moving dots to stare and the twins. "Why?"
"You're need is greater than ours", George explained. "We've already memorised it all. We know where all the passageways are."
"Take this, for instance", Fred said.
He pointed at a corridor on the third floor. Harry stared at it. As well as the corridors he had walked down for over two years, another one branched off, one he didn't recognise.
"Behind the statue of a one-eyes witch, there's a passage that lead to Hogsmeade", Fred continued. "Directly into the cellars of Honeydukes, in fact."
Harry scrutinised the map once more, then looked back up to the twins.
"There's nothing I can give you in return", he said.
"It's a gift from us", Fred said.
"Anyway", George continued, "There is something you can give us." He tapped the map. "Mischief managed."
The lines faded away. George folded up the now-blank parchment, and handed it to Harry.
"Thanks", he said, tucking the Marauders' Map into his cloak. "Um... so, what can I do for you?" he asked.
Rather than reply, the twins moved towards Harry. Nervously, the Gryffindor Seeker stepped back. Harry's back hit the door. Before he had time to open it, Fred and George were on him. Two pairs of hands moved across his body, caressing and kneading it in turn. George unfastened Harry's cloak, letting it fall to the ground, then focused on pulling off his sweater. Fred unbuckled Harry's belt, and slowly slid it out from his jeans. When Harry tried to half-heartedly push the twins away, Fred held the Seeker's hands behind his back, and used the belt to tie them in place.
"It's for your own good", Fred explained.
George had managed to take off Harry's sweater before Fred tied up his hands. Now, he unbuttoned Harry's shirt, one button at a time, and let it hang loosely. Taking advantage of Harry's exposed chest, George tweaked the Seeker's nipples, eliciting a whine from him. George watched his brother unzip Harry's jeans, and let them drop to pool at his ankles. Fred bent, and took Harry's left nipple in his mouth, while George took the right one. Sucking and nibbling, the twins make Harry moan.
Fred reached down, and fondled Harry's growing bulge. The roughness of the fabric of his boxers on his cock made Harry even harder. Fred then slipped his hand beneath the waistband of Harry's boxers. The touch of a foreign hand on Harry's cock made it jump and twitch. Fred's fingers curled around the engorged member slowly jerking Harry off. When Harry was about to cum, Fred pulled his hand out of the boxers, leaving Harry on the edge.
Now, the twins stepped back, admiring Harry as he stood half-naked, and writhing with pleasure. His cock was clearly visible tenting his boxers, and a stain of precum was forming where skin met the fabric. Fred and George gripped one side of the waistband each, and carefully lowered it. Harry's cock sprang free. When the Seeker was divested of his remaining clothes, the twins got undressed add well, and knelt in front of him. Fred held Harry's cock lightly in his hand, as George opened his mouth, and took the head inside him. Harry moaned loudly as George's tongue flicked around his cock. Slowly, George took more of Harry's cock into his mouth.
"Look at him", Fred ordered.
Harry followed the order. George had taken nearly all of Harry's cock into his mouth. His brother's hand pressed against the back of his head, pushing him to take more of the meat in. Harry could see George begin to choke as his cock blocked his airway. George's throat convulsed around Harry's cock, drawing a moan from the Seeker. Finally, Fred released his brother. George pulled away, coughing. Fred winked at Harry as his hand reached down to stroke him. George looked up at Harry, his lips swollen. Harry's got closer to cumming again, but Fred speed before he could. For a few seconds, Harry thrust his hips into nothing, trying to cum.
By this point, George was standing again. He kissed Harry on the lips. His tongue pressed against Harry's mouth, but the Seeker kept his mouth closed. While Harry was distracted, Fred knelt behind him, and spread his ass cheeks. When the Beater pressed his face to Harry, his tongue pressing into his hole, Harry gapped. George's tongue slid into Harry's mouth. The twins were separated only by Harry's digestive tract.
After a while both twins pulled away. Harry's eyes were closed, as he had reached the point where he was just experiencing what was happening to him. When he felt something hard press against his hole, though, Harry's eyes shot open. He started into George's face.
"Don't worry", the Gryffindor Beater said. "It's just Fred. If you relax, it'll be easier."
Harry tried to do what George recommended, but it was hard. Fred managed to push his cock into Harry's hole, moving carefully so that he didn't hurt the Seeker. Harry felt more filled than he ever had before. Slowly, Fred pushed deeper into Harry, then just as slowly pulled back. He increased his pace as Harry's hole grew looser. On the third pass, Fred's cock brushed against something inside him. Pleasure spread throughout him.
"Oh, yeah", Harry moaned. "That's good!"
"You like that?" George asked.
He was pinching and twisting Harry's nipples.
"Of course he does", Fred replied.
George knelt again in front of Harry, and resumed sucking his cock. He moved slower now, trying hard to prevent Harry from cumming straight away.
Finally, though, Harry, came. George pulled himself off his cock at the last minute, so Harry spilled his seed on the Beaters face. Fred pulled out of Harry, and the Seeker sank top the floor. Fred and George stood above him, beating their cocks in unison. Within seconds of reach other, they came on Harry's chest.
Fred and George dressed as Harry recovered, then helped the Seeker clean up. Fred handed the Marauders' Map to Harry with a wink.
"We hope it comes in handy", George said, as they left the room.