Title: The Invisible Line
Warnings: Age difference (43/17, attempted 41/15), profanity, mention of past character death, m/m slash sex.
Disclaimer: Belongs to JK not me; just borrowing the characters and having fun with them.
Author's Notes: Beta read by the wonderful kamerreon .

Written for hp_kinkfest on LiveJournal. The kink is the age difference.

The annual Weasley-Potter Christmas party at Grimmauld Place was in full swing in its usual loud and raucous fashion. Harry wished he were anywhere but there, not in the humour for celebrating, surrounded by all those happy faces. All he wanted to do was take a long hot bath, maybe have a wank, and go to sleep.

These last few weeks had been trying. A complicated murder case had kept him busy, and although they had apprehended the culprit yesterday, Harry knew there was a mountain of case-related paperwork waiting for him as soon as the Christmas break was over.

He mingled, he chatted with old friends and distant Weasley relatives, forever tied to them despite Ginny's death ten years earlier. With each new person he made time for – Neville, Luna, Seamus, Lysander, Fleur, Hugo, the list was endless – he edged closer to the door that would lead him out into the quiet of the hallway. From there he could retreat to the sanctuary of his own room and take maybe half an hour back for himself.

Grey eyes followed him; he felt them burning into his back, his neck, his hair. His son's friend and his old nemesis's only son, Scorpius Malfoy, watched him intently. Harry had to avoid his gaze. To look into those eyes might be his undoing, as they so nearly had been in the past.

Harry had almost crossed a line that he might never have come back from. Scorpius Malfoy, houseguest of Albus Potter and unrequited crush of Lily Potter, had been just fifteen years old when he had snuck into Harry's bed as he slept. Just thinking of that now…

He let the door close behind him and leant back against it wearily, pinching his thumb and forefinger to the bridge of his nose. Fifteen. Harry had been forty-one. Thank Merlin, he had found the will power to push Scorpius away. Even now, Harry didn't know how he had done it. Scorpius Malfoy was possibly the most tempting being of his acquaintance.

In his need to escape, Harry didn't bother with the stairs; he Disapparated straight up to his room. Just half an hour away from those eyes, that was all he needed to calm the insistent singing of his magic beneath his skin. He placed his wand on the side table, kicked off his shoes and collapsed back onto the bed with his eyes closed.

"You're avoiding me," said an amused voice.

Harry didn't open his eyes. "What do you want, Scorpius?"

"What I always want, Harry. You." The voice moved farther into the room. "I've spent three weeks perfecting the Silent Apparition Spell just for this moment."

Harry snorted. Only Scorpius would do that – invent something that the Ministry would pay a fortune for – for the sole purpose of surprising Harry like this. Scorpius was a genius, completely off the scale. "I reserve first dibs on the rights for that spell." Harry opened his eyes and glared at the blond intruder. "And you can't have me, remember? We've had this conversation."

"I'm of age now," Scorpius reasoned, inching closer to the bed. "Of age and very, very horny."

Harry should have expected it, but the boy was seventeen for Merlin's sake – he shouldn't know tricks like this. Harry certainly hadn't at that age, but then, he had been busy fighting Voldemort when he was seventeen and not trying to seduce men old enough to be his father, or even boys his own age. There had only been Cho, and then a few stolen kisses with Ginny.

A barely distinguishable flick of Scorpius's pale wrist divulged them both of all clothing and, a moment later, Scorpius was straddling him. Harry's prick was showing far more interest than Harry wanted to confess to feeling.

"I've never wanted anyone else," Scorpius said, his silver head bent as he trailed kisses along the nape of Harry's neck. "Since I was thirteen."

Harry swallowed and tried not to react to the sensation of that delicious mouth on his skin, to the sight of that expanse of ivory above him, to that secret confession. "Scorpius, I'm old enough to be –"

"I don't care how old you are, Harry. This is all that matters." He nibbled Harry's ear. Harry groaned, not stopping to wonder how Scorpius knew that particular spot, the top half of his ear, was the spot for turning him to putty. "I want to fuck you." Scorpius's warm breath chased across Harry's earlobe, and if he hadn't already been hard, those five words would have had him in an instant.

Years ago, when Harry had defeated Voldemort and had time to take stock of his life, he had finally had the gumption to admit that he liked men fucking him hard and fast, though he had no objection to the other way around on occasion. Those first two post-war years had seen him experimenting with both sexes, rather a lot, before giving into the pressure and the obligation he felt from the Weasleys and marrying Ginny.

"Want you so much, Harry," Scorpius whispered, his lips hovering above Harry's. "Let me, please." As he spoke one slender hand wrapped itself around Harry's erection and tugged, running his thumb over the tip as his tongue pressed its way into Harry's mouth.

Harry vaguely realised that he wasn't exactly fighting Scorpius off. His magic was thrumming with desire, as it always did whenever the youngest Malfoy slipped into his radius.

His moral compass had been pointing in the right direction until all the blood rushed to his cock instead. Harry felt his legs fall open to allow Scorpius better access. He groaned in barely controlled breaths as the hand around his cock slipped between this legs and a curious finger traced his entrance. His eyes flicked to Scorpius's, the silver grey eyes watching him closely as they kissed. Harry tipped his head and deepened the kiss. This was wrong; Scorpius was too young... Harry should be shagging men his own age.

The finger inside him stilled and Scorpius pulled back, biting his lip. "Tell me what you like, Harry," he said, licking his lips. "I've never –"

Oh Merlin, Harry catapulted over the invisible line. "Let me show you," Harry heard himself say, grabbing his wand and casting a quick lubrication charm. "Here" – he held out his fingers for Scorpius to scoop the liquid off them – "we could do it all the magical way, but –"

"No!" Scorpius shook his head. "I want to –" He broke off as he found Harry's hole again and pushed his finger back inside.

"Deeper," Harry instructed, levering himself up on his elbows so he could watch, the privilege of what Scorpius was giving him affecting him more than he would have expected. Scorpius pushed deeper, curling his finger and eliciting a moan from Harry and a, "More... another finger."

After several minutes, Scorpius added a third, following Harry's instructions to stretch him. Harry could take no more, feeling ashamed of the unchecked cries falling from his lips. Scorpius was flushed pink, his eyes wide as he watched his digits disappear into Harry, his gaze torn between watching that and staring at Harry. Lust shone from him in waves.

"Now, fuck me!" Harry needed that long, red cock in him, and he needed it now. The sight of it jutting out of a thatch of white blond hair, contrasted flat against that perfect, pale body was enough to tempt a saint. "Go slowly, all right? I don't want you to come too soon." Harry didn't want to come too soon either; this was something to be savoured. Plenty of time for hard and fast another day –

He shook his head. There could be no other day after this.

Scorpius sat back on his heels and pulled Harry's legs upwards, twisting his head to place a lone kiss on the inside of an ankle and letting them rest across his shoulders. He arranged his cock to nudge Harry's opening. "Harry –"

Harry rolled his hips. "Do it! I want it – I need it."

Scorpius nodded and pushed inside slowly, Harry muttering encouraging words as he was gradually filled with this beautiful boy, less than half his age. Fuck, that milky white flawless skin, untouched and – Merlin, he'd never felt so exposed. As soon as he felt Scorpius's balls tickling his buttocks he bucked upwards. "Scorpius," he whispered, his head falling back onto the bed.

Tentatively, Scorpius moved, one hand splayed on Harry's abdomen, the other gripping an ankle. When Harry tilted his hips and Scorpius's cock grazed Harry's prostate, Harry came undone. "Gah, Scorpius, please, faster – aaahh!" Scorpius obliged, the intense concentration on his face mixing with pleasure as he thrust himself into Harry.

Harry couldn't think. He forfeited the ability to breathe as he lost himself in the sensations swamping him, feeling his climax building in his belly, and curling his toes. His cock was still untouched, yet the feel of it against his stomach, Scorpius inside him, the sordid sounds of flesh slapping against flesh, the harsh breaths and barely controlled sighs of, "Harry. Harry. Harry," coming from Scorpius, all built up to one logical conclusion.

He closed his eyes and let the sensation wash over him; his orgasm poured out of him in wave after wave of unstoppable pleasure. He felt Scorpius still as he followed him with a cry of, "Harry!" Scorpius gently moved Harry's legs back to the bed and withdrew, dropping down beside Harry on his side, wriggling close.

It was approximately thirty seconds before the guilt flooded Harry and the last tingles of pleasure turned into molten dread.

Scorpius, sweat slicked and flushed, started kissing his way along Harry's frozen jawline. "That. Was. Amazing," he said between kisses. "When can we do it again?"

Harry couldn't speak; his throat felt as though it had been welded together. He squeezed his eyes shut and took a deep breath.

"Harry? What's wrong?" Scorpius, his voice uncertain now, sounded every inch the seventeen year old he was. Merlin, Harry had a son older than this boy. What kind of a filthy pervert was he?

Harry began to struggle up onto his elbows and, grabbing his wand, cast a quick cleaning charm and Summoned his clothes. His voice wouldn't function, but he maintained the rest of his motor-function it seemed.

He rolled away from Scorpius and sat on the end of bed, dropping his head into his hands briefly before yanking on his trousers. He felt Scorpius shuffle up behind him, long arms wrapping around his middle and a lightly stubbled chin perching on his shoulder. Harry stiffened at the intimacy of it.

"This was a mistake," he said in a low voice, his hands covering Scorpius's for a split second before taking one in each of his hands and removing them from around his waist. "I have clothes older than you."

There was a harshly drawn breath from behind him, followed by silence. Neither man moved. Harry couldn't let himself turn round. Tense minutes passed before there was a scrabbling behind him and Scorpius dropped his long limbs over the edge of the bed besides Harry, and a slightly shaking hand took his.

"We've been doing this for over six months, Harry," Scorpius said. "When are you going to stop doing this – to both of us – and admit we've got something going here?"

"I don't know," Harry answered softly. "When you turn twenty? I'm the bloody Head Auror. Your father, my kids –"

"This isn't about them, Harry. This is about us." Scorpius cupped Harry's jaw and turned his face towards his, dropping his hand to Harry's knee. "I'm eighteen next week. I'm of age. I'm yours. Please don't deny this any longer."

Harry hadn't known that grey could burn.

"Harry, you let me fuck you tonight," Scorpius stated. "That has to mean something."

It did. It meant Harry was head-over-heels for Scorpius Malfoy. He never let anyone… unless he trusted them, loved them. He scanned Scorpius's hopeful face and realised he couldn't do it again. It wasn't fair.

Harry tipped his head forward and kissed his Scorpius, sucking on his lower lip and threading a hand in his silky hair. "All right." He rested his forehead against Scorpius's. "Let me go wind the party up downstairs, then you're staying over."

Scorpius's face split into a rare grin. "Thank you, Harry. That's all I ask."

Harry nodded. One day at a time.

-o-0-0-o-

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