Tony slapped Loki hard. The sound of it rang out as Loki's face was snapped backwards by the blow. For a moment Loki froze, breathing hard, while Tony's handmark turned his pale cheek red, and Tony was filled with an unmistakable sense of triumph.

For a moment.

Then the sheer terror hit him. Because he didn't have his suit, he couldn't get to his suit - if he'd been wearing the suit right now he'd have sent Loki flying with a repulsor blast instead of slapping him like Loki had questioned his virtue. But Loki had just appeared, right in Tony's home, and stood there making snide remarks while Tony sweated and tried to sidle towards the door and wished the other Avengers were in.

And then, "and where is Miss Potts? She's usually so very attentive to your needs - " and Tony lost his temper.

Loki stayed still, his shoulders a little hunched, for several long seconds. Tony had long enough to thoroughly contemplate his oncoming death before he met Loki's eyes.

Tony had been around long enough to recognise the expression in them.

He grinned savagely, his stomach wooshing like it had as he fell towards the New York streets, and hit Loki again.

That time he got a gasp. Before Loki could speak, Tony slapped him again - as hard as he can, a good one that made Loki stumble a little.

By now his green eyes were aflame.

"No one's ever done that to me before," said Loki, his voice shaking a little - outrage and shock and lust. "No one would dare - "

"Shame," Tony interrupted. "I guess that's why you never realised how much you like it."

Loki's face twisted, his eyes flashing poison green. "You're suggesting - "

"Not suggesting. Stating." He'd gone way too far to back down now, and the way Loki's slim body was tensed for attack made Tony want to strip him down and show him what real vulnerability meant. "I see the way you're looking." Tony stepped forward, closer and closer, until he could smell Loki's skin. Awareness of danger sizzled through his body. "You're just dying for me to slap you again."

Loki's cheeks were flushing red even behind the marks where Tony had hit him. "Rubbish."

"Okay. Well, you're the god..." Tony backhanded him, feeling the swing of his arm and the connection and the way Loki reeled dizzily. Loki was a god, and Tony had hit him before: he knew it wasn't not the force of the blow that was putting that dazed look into Loki's eyes. "So I guess if you want to, you can stop me."

Something like anger built in Loki's eyes now. Tony felt a shock of adrenaline as he realised that Loki's offended warrior-culture pride might send him across the room any second now. He slid a hand round Loki's neck to cup his nape, twining his fingers in Loki's black hair, and got ready to ding him another good one. Keeping Loki off balance had never seemed quite so literal before.

But the grip on the back of Loki's neck, that solid pressure, had an effect Tony wasn't expecting. For one long moment, Loki's eyelids fluttered, and the hard lines of his body softened just a little.

Just a little. But it was enough pliancy for Tony to have Loki across the room and standing by the bed in a matter of seconds, towing him over by the hand at the back of his neck.

Practice at getting to the bed fast might actually save his life. Take that, Pepper's eyeroll-face.

Because Tony held Loki for one more second and then slapped him, feeling his own skin tingle as it connected. Loki staggered and fell onto the bed, shaking his head dizzily, and Tony followed him down.

Fucking Loki was an exercise in keeping him off-balance, in fucking with his head enough that he couldn't keep his nasty thoughts together. And it was amazing. Tony Stark, professional risk-taker and thrill-seeker and chaser of physical extremes, couldn't have found a better consummation than this squirming supervillain underneath him, whining as Tony stroked him through his clothes.

Tony wondered what they'd do about the armour, but it was fine: as Tony's hand teased Loki through his leathers, Loki whined in frustration. His hands, twisting in the sheets, glowed green and then they were both bare.

Tony froze for a moment, then went on: he could forgive all this magic in his personal space if it meant he got this sudden expanse of warm skin, the sudden revelation of curves and scars and movement behind Loki's rigid armour.

Loki's eyes were wide, almost confused, as Tony played and teased. For a wonder, he didn't speak. But Tony drew a moan, a gasp, a little cry as Tony worried at pink nipples with his teeth. Before long, Loki was giving a near-continuous stream of whimpering sounds as Tony put him through his paces.

And it felt like a revelation when Tony made a space for himself inside Loki's icy shell. Loki gave small, shuddering sounds, his thighs trembling around Tony's forearm as Tony pressed slicked fingers inside him. And then Tony's mortal body was making Loki shudder and cry out, his face still marked from Tony's hands, his neck and chest coming up in bruises from Tony's mouth.

Gorgeous.

And Tony allowed himself the tiniest sly smile as he shoved Loki irrevocably off his pedestal. But maybe that was why Loki got off on getting slapped: not just the pain, but the loss of dignity. Maybe that was how Tony could push until Loki was crying out underneath him, moving and shifting and meeting every thrust with that long, muscular body, and finally screaming when Tony dealt him one last slap.