A/N: I asked my bestest bro for a prompt. I got: "Loki and Tony. Loki needs to tell Thor, but Tony won't let him!"
A bit of smut was encouraged, and this is the result. So, yeah. FrostIron smut ahead, you've been warned, etc.

Crossposted to my AO3 account and all that jazz. Sharing is caring.

The master suite was pitch black, save for an ethereal blue glow that shifted on the bed every so often. Grunts and moans echoed throughout the cavernous room, the darkness swallowing up the sounds even as the couple on the bed continued their efforts to drive each other wild.

Tony gasped as Loki bit down on his shoulder, hips thrusting upwards. The god sank deeper, and they both moaned, mouths fusing together in a frantic rush for completion. Loki snapped his hips forward, grunting as he pounded into his mortal, then leaned close, his lips brushing his lover's ear.

"I think we should tell Thor," he rasped, punctuating the statement with another thrust.

Tony's eyes snapped open, the glow of the arc reactor reflected in them as he stared up at Loki, mouth agape.

"What in the ever loving FUCK, Loki?!" He growled, pushing the other man off. They both knew that Loki only went because he wanted to, and allowed Tony to roll away from him to sit on the edge of the bed. "Lights, JARVIS!"

The AI complied, low level light flooding the room and illuminating Loki's solemn countenance.

"It's imperative that we address the issue, Tony," Loki replied.

Tony groaned, threading his fingers through his hair. He'd let it grow out, because Loki preferred him with long hair. Just another bullet on a long list of things that Loki preferred.

Sometimes, Tony felt like a dog, eager to please his godly companion.
But this is where he drew the line. He would NOT go and tell Thor over a dinner of Pop-Tarts that he'd been fucking his little brother for well over a year.

No. No fucking way.

Loki hummed, cupping the back of his neck. Tony's shoulders slumped, and Loki took the opportunity to crawl across the bed, draping himself over the engineer's back.

"We must tell him, Tony...otherwise, I will be sent back to Asgard," Loki murmured.

Tony jerked away, eyes wide in shock as he whipped his head around to stare at his lover.

"What the hell is that supposed to mean?" The genius demanded as he got to his feet, hands planted on his hips.

Loki bit his lip, not wanting to tell Tony that he was at his most nonthreatening when he wasn't wearing anything. Squashing the urge to gather the man into his arms, Loki settled for sliding to the edge of the bed, steepling his long fingers under his chin.

"I have no reason to stay on Midgard. The Allfather stipulated that I must have a 'keeper'," he remarked bitterly. "I will not allow Thor dominion over my freedom."

Tony raised an eyebrow, taking a deep breath before crossing his arms over his chest.

"And what makes you think that Daddy Odin will let me watch you? Should I start a babysitter's club with Thor? Campfires and friendship bracelets?"

Loki rolled his eyes, knowing that over half of Tony's blathering was misdirection. He didn't really know why the man continued trying to mislead the God of Lies.

"Perhaps Odin already knows that we share a bed," Loki quipped.

Tony made a choking noise, not really wanting to consider the implications of the Allfather knowing that he was getting freaky with his youngest. Or that creepy gatekeeper, for that matter.

"Fuck," Tony spat, starting up a line of pacing from the bed to the window and back.

"I agree. We should get back in bed. After we tell Thor."

Growling, Tony made another circuit, his hands tugging his hair at the roots.
"Why the fuck is this so important? Why can't we just continue on as we have been? Fuck each other's brains out, check. Fulfilling relationship where I don't find my solace in the bottom of the bottle, and you don't conquer the world, check. Telling big brother Thor so he can crumple me in my suit and toss me off the Empire State Building? Fuck no."

Loki sighed, pinching the bridge of his nose. What was the Midgardian phrase? Biting the bullet?
"Stark...We need to tell Thor, because he will be officiating the ceremony."

Tony faltered, the blood draining from his face. It seemed as if all the air had been sucked out of the room, and was that the arc reactor failing in his chest? Jesus fuck. He thumped a fist against the glass casing, coughing as the gears started to whir in the back of his head.

"Loki...what the fuck are you trying to tell me. No lies. I need some honest shit right about now."

"I may have told the Allfather that we were engaged to be married," Loki wheedled, leaning back on the bed while kicking his legs out, crossing his ankles.
"No. You are NOT making an honest woman out of me. Or vice versa. Fuck no. I'm not the marrying type, Rudolph. Bull fucking shit."

Loki shrugged, examining the nails on his right hand.
"Then I go back to Asgard. And you need not fear Thor's wrath. I am no blushing bride, Tony. Thor knows I am far from virginal. I wish to be the one to inform my brother, instead of him finding out from one of Odin's ravens whispering in his ear."

"Is your dad really going to cockblock us?"
"The Allfather is a problem, but he will not be the one banging on your door, demanding your blood as recompense for not telling him sooner."

Swallowing hard, Tony walked back the bed, stepping in between Loki's legs.
"You could have warned me, you know," he murmured, resting his hands on the god's shoulders, thumbs stroking up and down the sides of his neck.

Loki arched like a cat, humming as he wrapped his arms around Tony's waist, pulling him flush against his chest.

"I apologize, love," he replied, though Tony had his doubts of his sincerity.

Pulling Tony's head down, Loki pressed his mouth to the engineer's, tongue probing until it gained access. The kiss escalated, until Tony pushed his lover back onto the bed, straddling his waist.

"Maybe we could work something out," Tony gasped as Loki wrapped his hand around his cock, pumping it several times. The god trailed his hand over Tony's ass, fingers pressing inside.

Digging his nails into Loki's shoulders, Tony threw his head back, moaning as Loki began to scissor his fingers, quite expertly if anyone would have asked.

They both jolted as the bedroom door rattled in its frame, a staccato beat of pounding starting up not a second later.

"STARK!" Thor boomed. "I WOULD HAVE WORDS WITH YOU!"

Tony dragged his gaze from the door to Loki, baring his teeth at the trickster's smirk.
"Sneaky fuck."

Thanks for reading!