Warning, this story contains very mature stuff! Don't like - don't read. Otherwise, enjoy!
"Where's Lucy?" the dragon slayer asked as he came bursting through the unlocked door of Erza's hotel room.
"Probably in her own room," the fairy woman said unfazed, not even lifting her eyes off the gleaming steal sword in front of her. "She said she'd take a shower to get rid of all that dust."
"Right!" Natsu said and turned on the spot, a wicked grin spreading all over his face as he marched off towards the celestial mage's room.
"Don't disturb her!" Erza warned him with a dark tone in her voice, but Natsu didn't hear her, he was already long gone.
"Hehe," the pink haired young man laughed mischievously. "Lucy will be so scared!"
Silently, he pulled his scarf up around his face as he crept through the hotel corridor down to his partner's room.
"Ninja style!" he whispered enthusiastically under his breath as he turned the doorknob. The door swung open without any further resistance and the dragon slayer celebrated his success with what he thought was a cool ninja pose. "Nin-nin!"
He pushed open the door and stuck his head in. No one there. She must really be in the shower.
"Too bad Happy couldn't be here for this," Natsu said to himself as he wriggled inside the room and crawled up to the bathroom door. "I'd love to see his face when I surprise Lucy!"
The dragon slayer saw the steaming heat coming from the bathroom door before he felt it. Carefully, he pushed his ear up against the warm wood to eavesdrop on the subject of his prank. Yes, he could hear the water running. Definitely showering.
"How 'bout a round of tickling," Natsu giggled mischievously as he planned his attack. "And maybe some-"
Suddenly, the dragon slayer's line of though was interrupted as he heard something totally unexpected through the thick wood of the bathroom door. It wasn't the sound of running water or the sound of something falling off the shower shelf. It was a deep and rumbling moan coming from the woman inside.
"L-Lucy?" the pinkette wondered as he pushed his ear closer to the door.
"Ngh Natsu..." Lucy's soft voice gasped and Natsu felt his cheeks burn.
"That's it, Natsu!" the celestial mage said between heavy breaths. "Faster, please, faster!"
Natsu froze. He couldn't see her but he could smell her, and in his mind he imagined how she must look: her naked body dripping wet under the steaming rays of water as she pleasured herself. His name rumbling softly off her pink lips.
"Lucy, what are you doing to me?" he mumbled under increasingly heavy breaths as he felt a familiar ache in his groin. "This isn't fair!"
"Aaaaaah! Natsu!" the celestial mage's voice cried out and her words were like magic to Natsu's spellbound body, releasing the paralysis and sending shivers through his heated limbs.
"Fuck, Natsu!" the blond hissed and now the dragon slayer could actually hear the slick sounds of her fingers thrusting in and out of her wet centre. "Oh yeah! Natsu!"
That was it. Natsu didn't care if he was found or if he spilled himself on her floor. In an instant he'd pulled down his pants just enough to release his throbbing erection. It towered up towards his belly and for a second he felt like it was looking at him, staring and judging his perverted actions. But all common sense went out the window as he grabbed his cock and began pumping himself hungrily.
"Yes! Oh, Natsu please!" the celestial mage's voice panted so close to him that he could practically feel the heat of her breath on his sweaty skin. "Ughn-"
"Shit, Lucy," he hissed as he felt the familiar build up in his stomach.
"That's it Natsu!" Lucy cried out as she reached her own peak. "Fuck me!"
"Don't need to tell me twice," Natsu groaned as he picked up his speed and ground his teeth at the sensation of his rough hand rubbing up and down his erect member.
"Fuck my pussy-" the celestial mage moaned as stars filled her eyes. "-with your big, AH, hairy, NGH, cock!"
"Ah, Lucy you're so bad," the dragon slayer growled and closed his eyes as his hand continued its quickened pace. "I like it."
"Take me Natsu!" the blond moaned as the last of her high was pounded out of her. "Take me, take me..."
She repeated her words over and over, with a rhythm so soft yet demanding that it helped Natsu over his own edge, sending him into complete and utter bliss.
"Shit, Lucy!" he hissed. "I'm gonna cum-!"
With those words he released the shackles on his climax and felt his seed spill all over his stomach, chest and legs. Quickly, he cleaned up the mess and retreated to his favorite part of her home: the soft, pink bed which smelt exactly like her. Nestling his face into the rustling cotton sheets he drew a sharp breath and inhaled the sweet aroma of his partner. Moments later, the celestial mage appeared in a cloud of steam as she stepped out of the bathroom. Her wet hair gleamed in the moonlight and covering her bare skin were tiny pearls of water that glistened as the stars shone upon them.
"Natsu?!" she gasped as she saw the outline of a body hidden in her bed.
The dragon slayer closed his eyes and awaited his punishment, but nothing happened. Suddenly, something weighed down the mattress next to him and he felt her soft fingertips caressing his pink spikes.
"He looks so peaceful when he's asleep," Lucy said with a sigh as she leaned down to lay beside her partner.
"Lucy..." the dragon slayer hummed, already feeling the drowsiness of sleep washing over him.
"I'm right here," the celestial mage said with a smile that didn't fade, not even when Natsu's strong arm wrapped itself around her and pulled his warm body closer to hers.
"That was a nice shower," the sleeping young man mumbled as he nuzzled his nose into her blond locks.
Lucy immediately tensed. What did he say? Had he heard her? Oh, sweet Mavis please let this be a misunderstanding!
"Good night, Lucy..." the dragon slayer whispered as he dozed off.
The celestial mage felt the color on her face rise like the liquid in a thermometer. Paralyzed and stiff she lay awake all night listening to her partner's soft snores.
"Natsu, you baka!"