Natsu takes Gray to the mountains for his fiftieth birthday, and the hot tub at their cabin is the perfect place to celebrate.

-----

"This was an amazing idea."

Gray stood outside the car, surveying the cabin as Natsu grabbed their suitcase from the trunk. Snow fell lightly around them, leaving a white dusting of flakes across Gray's dark wool jacket. He sighed happily, breathing in the mountain air and tipping back his head to look at the bright, cool sky.

"Better than a huge birthday party full of people you don't wanna talk to?" Natsu teased, closing the trunk and poking Gray in the ribs. Gray rolled his eyes, then turned and kissed Natsu on the nose.

"You know it is," he said, reaching out for the suitcase. Natsu shook his head and nudged Gray toward the cabin.

The path from the car to the front door was packed snow, and walls of it rose up to hip-height on either side. A string of white Christmas lights hung from the A-frame of the building, casting a pretty glow on the dark wood. Tiny square windows were set on either side of a rustic, wooden door, and a thick layer of snow hung heavy across the roof.

"Do we even have cell reception up here?" Gray asked, pulling his phone out of his pocket.

"Nope," Natsu replied, grabbing the phone and shoving it into his jacket. "There's a landline for emergencies, but for now you're stuck with just me."

Gray laughed, grabbing Natsu's hand and pulling him toward the cabin. "I think I'm okay with that," he said.

The inside of the cabin was small and cozy – just enough room for the two of them. A small set of stairs led up to a loft with a bed, and a stack of cedar logs sat next to a fireplace with two chairs set nearby.

"This is like a book," Gray murmured, running his fingers over the wooden countertop. Everything in here was deep and rich, natural light spilling in through the windows and illuminating their tiny home for the next few days.

"It, uh, reminded me of The Hobbit," Natsu admitted, setting down the suitcase and kicking off his boots. He tugged Gray's jacket off and tossed it on the back of a kitchen chair, then wrapped his arms around Gray from behind, kissing the back of his shoulder. "Remember, it was the first book you read to me?"

Gray laughed, putting his hands over Natsu's on his stomach and sighing happily. "That was a long time ago," he murmured. "Twenty... six years?" he guessed.

"Thirty," Natsu corrected. "We've been married for twenty-six."

"That makes me feel old," Gray muttered, turning around in Natsu's arms.

"You are old," Natsu said, grinning and wrapping his arms around Gray's waist. "Ancient, even. Half a century."

"God, don't say it like that," Gray said, making a face. Natsu grinned, bringing his hands up to Gray's face and running his fingers down the stubble on Gray's chin. "I'm fifty, not dead."

Natsu laughed, leaning in and kissing Gray. Then he pulled back and gestured toward the back door. "Wanna go in the hot tub?"

~

Twenty minutes later, Gray was sighing happily, head tipped back against the edge of the hot tub while he watched tiny flakes fall from the sky. Seeing them twist and blow into tiny flurries was mesmerizing, and he laughed as he saw Natsu stick out his tongue to catch some.

"You're a dork," Gray said, flicking water at Natsu, who looked indignant.

"Your face is a..." Natsu trailed off, choosing instead to splash a much bigger wave at Gray and bursting out laughing when Gray sputtered and wiped at his face with the back of his hand.

"C'mere, you," Gray said, pushing himself off the edge of the hot tub and grabbing at Natsu, who yelped and tried to squirm out of the grasp. He was too late, though, and just managed to take a deep breath before Gray dunked him under the water. When he resurfaced, Gray was leaning back again, laughing as Natsu shook out his hair.

"Y'know, I'd retaliate," Natsu said, reaching out and grabbing Gray's wrists, "but I love watching you laugh."

Gray's cheeks immediately turned pink. "You're a sap," he mumbled, but the smile didn't leave his lips.

"'s only 'cause I've got a gorgeous husband," Natsu said, pulling Gray close under the water and letting go of a wrist to run his fingers through Gray's hair. He tightened his fingers, then kissed Gray – much less chaste than earlier. Gray sighed, breathing into the kiss as he wrapped his hands around Natsu's waist underwater. Neither of them wore swim trunks, and the Gray's hands slid smoothly against Natsu's skin.

"You got a place with a hot tub just so we could fuck in it, didn't you?" Gray asked against Natsu's lips. Natsu laughed, nudging Gray backward so he could straddle Gray's hips. The hot water slid across his skin and he shivered as flakes of snow melted across his shoulders.

"I don't see you complaining," Natsu murmured, slipping his legs around behind Gray until he was sitting in Gray's lap, then running his tongue along Gray's lower lip. Gray's hands moved down to Natsu's ass, sliding his skin before pulling him close. Natsu groaned as Gray pushed his hips up and their cocks slid together.

"What do you wanna do?" Gray asked, hands roaming up Natsu's back. "Probably not a good idea to actually fuck in here."

"It's your birthday," Natsu replied. "What do you want?"

"I wanna make you feel good," Gray replied, voice low. Natsu shivered, biting down gently on Gray's lip before pulling back and gazing into Gray's dark eyes. He pressed their foreheads together, then nudged one of Gray's hands up. Gray hummed, bringing his hand to Natsu's throat, then drifting his fingers slowly across Natsu's chest.

Natsu let out a soft breath as Gray's thumb traced a gentle circle around his nipple – almost touching, but not quite. "You're a tease," Natsu murmured. Gray hummed in agreement, nudging Natsu's head to the side and kissing his neck. Natsu shivered as Gray bit down gently, then began to press kisses across to his shoulder.

"You like it," Gray said, words tickling Natsu's skin. He traced slow circles around Natsu's nipple with his thumb, ignoring Natsu's not-so-subtle nudging, and still avoiding where he wanted to be touched. Natsu made a quiet sound of protest that quickly turned into a moan as Gray's tongue flicked across his collarbone.

"Gray," Natsu whispered as Gray dragged blunt nails across his chest, drawing feather-light circles around the other nipple as he kept kissing along Natsu's shoulder. "Please."

Gray laughed against his skin, using his other hand on Natsu's lower back to pull him closer until they were pressed together everywhere except their chests. "I like teasing you," he murmured, moving his fingers slowly around Natsu's nipple and brushing lightly against it before pulling back.

Natsu groaned, jerking his hips forward and gasping at the hot, wet friction between them. Steam was starting to curl the strands of hair that were plastered against the back of his neck, and when a chilly breeze blew across his shoulders, he shivered, skin suddenly much more sensitive under Gray's fingertips.

Gray dipped his head, kissing down across Natsu's chest until Natsu could feel hot breath against his nipple. Gray's tongue flicked out, barely touching him, and Natsu moaned, fingers tightening in Gray's hair.

"God, I love how much you love this," Gray murmured, brushing his thumb over one nipple while tracing his tongue around the other. "I love making you feel good."

Natsu was about to reply when Gray pressed his tongue flat against Natsu's nipple, then closed his lips around it and sucked gently. "Fuck," Natsu hissed, the sensation sparking straight to his cock as he ground against Gray. Gray's teeth scraped the sensitive skin as he caught Natsu's piercing between his teeth and pulled gently. "Harder," Natsu whispered.

Gray hummed, biting down gently on Natsu's nipple before tugging harder on the piercing with his teeth. The slight pinch of pain arced through Natsu's body, and Gray repeated the motion while rubbing his thumb over the other side. Every part of Natsu vibrated with the sensation and he couldn't help the deep, rough groan that passed his lips.

"There you go," Gray whispered, sucking hard again before pulling the piercing on the other side. Natsu whimpered and Gray pulled harder, dragging his thumbnail across Natsu's nipple at the same time. Gray's cock slid across Natsu's as Natsu squirmed in his lap, leaving pretty red marks across Gray's back with his fingers.

"Harder," Natsu begged again and Gray obeyed, licking and sucking eagerly at Natsu's nipple while twisting the piercing on the other side. Then he pinched Natsu's nipple, hard, and Natsu cried out, jerking against Gray. Gray pulled back, ignoring Natsu's protests as he slid his hand down Natsu's abs under the water, fingers brushing against his cock.

"Can I?" he asked, other hand gripping Natsu's ass tightly.

"Y-yeah," Natsu stuttered, reaching down and taking Gray's hand in his own. "Just—"

"I know," Gray said, returning his lips to Natsu's neck as he rubbed his thumb over the head of Natsu's cock, ignoring the rest of it entirely. "Like that?"

"Fuck, yes," Natsu groaned, running his hand over Gray's cock and enjoying the stuttered breath against his skin. Gray's fingers traced the head of Natsu's cock, rubbing gently as his other hand came back up to Natsu's chest and toyed with his nipple. Natsu groaned, feeling the water slide along his skin as they moved against each other.

"Do you want me to use different words?" Gray asked, sucking at Natsu's nipple piercing again. Natsu let out a shaky breath, jerking his hips up into Gray's hand. They'd done it a few times, using words like 'breasts' and 'cunt' and 'clit' when Gray touched him. At first it had left Natsu feeling vaguely unsettled – he wasn't a woman, didn't want to be a woman. But sometimes being a man wasn't quite right either, and eventually it had become comfortable when Natsu was in a particular headspace.

"Yeah," he said after a second, groaning as Gray bit down on his nipple, then tipped his head up for a kiss. Gray never judged, never laughed, never asked questions that Natsu couldn't answer. Gray was always Natsu's safe place.

"Then how 'bout we go inside so I can eat you out?" Gray murmured against Natsu's lips, thumb still dragging over the head of Natsu's cock.

~

They made it up into the bed in record time, and soon Natsu was lying on his back on the pillows, legs spread while Gray settled between them. Gray leaned down and ran his tongue over the head of Natsu's cock, circling it slowly as he trailed his fingers down to Natsu's ass.

Natsu gasped and tipped his hips up as Gray pressed his thumb gently against Natsu's ass, sucking hard on his cock.

"You gonna tell me what you want?" Gray asked, pulling off and looking up at Natsu through a messy fringe of hair. "Or you want me to tell you what I'm gonna do to you?"

A pretty pink flush ran up Natsu's chest to his cheeks, and Gray wasn't sure how much of it was from embarrassment. He knew Natsu liked it when Gray talked to him during sex, but sometimes it was important for Natsu to say it out loud.

"W-want you to..." Natsu trailed off, squeezing his eyes shut and tipping his head back against the pillows. Gray smiled, pressing a kiss to the head of Natsu's cock.

"You want me to lick your cunt?" he asked quietly, bringing one hand up to rub across Natsu's cock as he ducked his head down between Natsu's legs. "Play with your clit? Finger you?" He ran his tongue across Natsu's ass and Natsu moaned, running his fingers across his own chest as Gray's thumb brushed over the slit of his cock.

"Yes," Natsu whispered as Gray's tongue pressed harder. "All those—that, y-yeah."

"How 'bout I do all that and then you ride me?" Gray said, and Natsu trembled underneath his fingertips.

"Yeah," Natsu whispered, reaching down and twisting his fingers in Gray's hair as Gray's tongue pressed against him again. "Fuck, Gray..."

Words were lost as Gray started working on Natsu in earnest with his tongue, hot and gentle as he dug his nails into Natsu's thigh. Natsu panted and squirmed above him, skin hot and flushed under Gray's fingertips. When Gray pulled back, he was greeted by the sight of Natsu's trembling, sweaty chest and bright red cheeks.

"You're all wet for me now," Gray murmured, moving his hand down to Natsu's ass and slowly slipping one finger in. Natsu arched up against the touch, fingers still tight in Gray's hair. "Wet and tight. You want me?" Natsu nodded, panting as Gray thrust his finger in and out slowly. "Say it," Gray said, gently adding another finger as he moved up and flicked his tongue across Natsu's nipple. "Tell me you want me."

"Gray, fuck," Natsu moaned as Gray stroked his thumb across the head of Natsu's cock, biting down on his nipple at the same time. "Want—th-that, want you, wanna..."

"What do you want?" Gray asked, tugging on Natsu's piercing with his teeth again. "You want me to suck your clit or you wanna ride me?"

Natsu shuddered as Gray added a third finger, sucking on his nipple at the same time. Then he opened his eyes and stared at Gray, eyes wide and cheeks red, before whispering, "ride you."

Before Gray could say anything, Natsu sat up, pulling hard on Gray's hair as he kissed Gray's neck. Gray gasped, tipping his head to the side. "Get on your back," Natsu growled, nipping at Gray's earlobe before letting go and pushing him down onto the bed.

Gray bit back a grin as Natsu took control, straddling his hips and staring down at him with wide, wanting eyes. When Natsu leaned over to fumble in their bag, Gray nipped at his chest playfully.

"Behave," Natsu said as he sat back up, poking Gray in the ribs. He tore open a condom packet and when Gray raised an eyebrow, he shrugged. "I think we're a bit too old to be ruining hotel sheets."

Gray snorted, grabbing the condom from Natsu and rolling it on. "You don't really want me to behave," he murmured, kissing Natsu's chest.

"I really don't," Natsu breathed, reaching between them to run his hand over Gray's cock. Gray tipped his head back against the pillows and let out a long, low moan at the sensation, digging his fingers into Natsu's hips.

Then Natsu sat up, shifting until he was over Gray's cock, and slowly slid back down, taking Gray inside him.

~

Natsu took several shaky breaths as he settled into Gray's lap, one hand splayed on Gray's chest, the other on Gray's hip. He closed his eyes, letting himself imagine for a second that he had another body, that Gray's cock was sliding into him in a different way, that he was rubbing a clit instead of brushing his fingers over the head of his cock.

Gray stilled beneath him, thumbs rubbing gently over Natsu's hips as Natsu exhaled, leaning forward and imagining curves instead of hard muscle, soft breasts instead of his flat chest.

"You okay?" Gray asked, voice soft. Natsu opened his eyes slowly, taking in Gray's dark, intense gaze before nodding.

"I just..." It was hard to explain. It wasn't dysphoria like Ryos or Freed had explained it – there was nothing Natsu hated about himself, nothing that made him feel like his body was wrong and he wished he weren't in it. But sometimes it felt good to slip into that headspace, and to picture Gray fucking him in a completely different way.

"You don't have to explain it," Gray murmured, running one hand up Natsu's side and back down again to grip his ass. "Does it feel good?"

Natsu answered by leaning back and resting a hand on Gray's thigh, then rocking forward on Gray's cock. Gray gasped as Natsu repeated the motion, rolling his hips as Gray's fingernails dug into his skin.

"Fuck, you feel so good," Gray groaned, guiding Natsu's hips back again and thrusting up into him. "Look good, too. I like watching you up there, taking me like that."

"Yeah?" Natsu managed as he shifted and let out an embarrassingly loud whimper.

"Yeah," Gray replied, running one hand up Natsu's chest and rubbing his thumb over Natsu's nipple. Natsu shivered and rocked forward again as he stared down at Gray's face – wide eyes, bitten lips, red flush across his cheeks. "I love you," Natsu whispered, leaning forward and pressing his forehead to Gray's.

Gray was perfect – touching all the places inside Natsu that made him feel needed and alive. His hands roamed across Gray's body as Gray thrust up into him, fingertips skimming soft skin as he pressed kisses to Gray's cheeks, his throat, his shoulder. He could barely hear the words Gray whispered into his ear over the sound of his heart pounding, but when Gray's breath started coming quicker, Natsu ground down harder and tightened around him.

It only took a few more thrusts from Gray for Natsu to come, eyes squeezed shut and Gray's name on his lips as he shook and shuddered. Gray's fingers dug into his hips as he kept going, moaning and whispering Natsu's name.

"C'mon, baby," Natsu gasped. "Wanna feel you come in me, you feel so fucking good."

"Natsu!" Gray ground out, thrusting up one last time as he came, head pressed back into the pillow. Natsu could feel Gray's heart slamming in his chest and he kissed Gray's neck, breathing unevenly against his skin.

After a moment, Natsu pulled back and stared down at Gray, who was looking up at him with a soft smile on his face. "Hey, you," Natsu said, kissing his cheek, then his nose, then his lips.

"Hey, yourself," Gray murmured, grabbing Natsu's hips and flipping him over until they were facing each other. He reached over the side of the bed to toss the condom in the garbage, then pulled Natsu into his arms, curling up and pressing his head to Natsu's chest.

They lay in silence for a while, listening to each other's heartbeats, until Natsu finally whispered, "thank you." Gray shook his head, kissing Natsu's chest.

"Don't thank me." He ran his fingers down Natsu's back. "I love you all ways – whoever and whatever you want to be."

"Now who's the sap?" Natsu muttered, but Gray could tell there was genuine appreciation beneath the teasing tone.

"Me," Gray said, leaning back and sliding his arm under the pillow. "'cause I have the most thoughtful – and hottest – husband in the world."

Natsu hummed happily, running his fingers through Gray's hair as they tangled their legs together. He kissed Gray's nose, then reached down and tugged the duvet up to cover both of them. "What do you wanna do tomorrow?" he asked, drowsiness creeping into his voice as he slipped his fingers between Gray's and squeezed his hand tightly.

"Doesn't matter," Gray murmured, kissing Natsu's temple and pulling him close, "as long as I'm with you."