Sanji doesn't even realise that Zoro is in trouble until the man flies backwards across his field of vision in a stream of smoke with an 'aaaAAAAaaaa!' as he hurtles past. He turns his head to see a slight brown haired woman with her palm outstretched and stream of smoke issuing from her palm.
"Let's see how fucking quick footed you are now asshole." She snarls and runs off. Sanji lets her go, the rest of her crew have mostly escaped after realising that the Straw Hats had them outclassed. Well, he thinks with a smile, most of them outclassed the others.
"Where'd Zoro go?" Luffy asks looking around now that the attacking pirates have fled. Sanji sashays forward and lights himself a little victory cigarette.
"Perhaps in the warehouse with the marimo-shaped hole in the door?" He suggests smugly. Oh he was going to rub this in terribly, Zoro would be so mad.
"Why's he not come out already? Usually he's back in a fight right away." Nami frowns as she casually dismantles her clima-tact and eyes the warehouse suspiciously.
"Maybe he's hurt!" Chopper squeaks worriedly and the crew as one walk slowly over to the warehouse. It was freaking typical of course, they'd only been on this island a few days before Luffy had accidentally picked a fight and a brawl had broken out. The fact that the fight was so routine was going to make Sanji's job at teasing Zoro all the more enjoyable.
Franky shoves what little is left of the door to the warehouse after Zoro crashed through it to the side and enters cautiously. Sanji and the rest of the crew follow after. He glances around the warehouse, it's apparently mostly used to store rum, there are barrels everywhere and several of them are cracked open from Zoro's forceful entrance. Wary of causing a fire Sanji stubs out his cigarette on the heel of his shoe and tucks the almost completely unused cigarette in his breast pocket.
They walk further into the dim light of the warehouse looking around for Zoro, but he's still nowhere to be seen. Sanji's foot catches on something unexpectedly and he looks down to inspect it.
"Zoro! Zoro, are you in here?" Luffy yells loudly but gets no response. Sanji frowns and picks up the black cloth on the floor, it's only when he holds it up that he realises what exactly he's holding and his grin becomes so wide that he thinks his head might split in two.
"I think I know why Zoro's hiding." He chuckles and holds them up for the others to see. The black fabric that Sanji's foot had caught on was Zoro's trousers. They're all ripped up and split, but they're definitely his. To add insult to injury he knows full well that Zoro doesn't ever wear underwear, so the man's hiding somewhere in this warehouse bare-assed and probably as embarrassed as hell. It's one thing to lose a fight, but it's another entirely to have to retreat back to your own ship naked below the waist.
"Oh great. I think I'm going to stay right here, I don't need to see that." Nami groans and covers her eyes.
"Oh, look what else we've got here." Usopp remarks and picks up Zoro's green waistband which is also split up the back as if it ripped apart at the seams. Along with it are Zoro's three precious swords hanging from a busted belt.
"Oh Zoro, we know you're in here~" He calls sweetly, his grin devious.
"I- I'm over here." Zoro calls back weakly from the other side of the room.
Sanji chuckles and he and the rest of the crew, minus the lovely ladies of course who have stayed back for the sake of their own modesty, make their way through the maze of stacked barrels. Zoro might have been thrown back there, but the place is remarkably easier to cross when you're seven feet off of the ground and hurtling backwards. In fact if Sanji strains his eyes in the dark he can see the high dent in the wall where Zoro obviously hit. He hops over a crate to see Zoro's stupid marimo head sticking out of a barrel. He's chin deep in a barrel, his fingers clenched tensely on the side.
"Missing something marimo?" He asks teasingly and triumphantly holds Zoro's ripped and tattered trousers aloft.
"You can say that again." Zoro mutters irritably and submerges himself a little further into the barrel of rum so that only his eyes and stupid hair are visible.
"Come on Zoro, we don't have all day. You can wear my shirt around your waist or something on the walk back." Franky suggests with a sigh and starts to shrug out of his loud shirt.
"I… I don't think that's going to help. I think I'll just stay here." Zoro responds, lifting himself out of the barrel just enough to answer before sinking lower, his cheeks and ears reddening gloriously. Sanji is starting to crack up with laughter, he's trying not to though and is biting his knuckles to hold it inside, but Zoro's embarrassment is just so delicious.
"Oh for goodness sake, you've not got anything we've not seen before Zoro!" Franky huffs irritably and crosses the distance to the barrel in two long strides. He plunges his large hand into the rum and snags Zoro by the back of his shirt and lifts him like a kitten or something.
"Ah, no! Believe me, you're wrong about that!" Zoro squeaks, but Franky just hauls the man completely out of the barrel anyway.
Sanji's jaw has already hit the floor in shock before the green fin does.
Where Zoro's legs were- where they should be- is instead a long sleek tail. Zoro is still human… mostly until his hipbones at least, at which point green scales start. They're the same green as his hair, light and mossy coloured, but the texture of the scales and the sparkle of liquid on them almost makes the colour look gem like. The tail is long, thick and powerful looking and Sanji can understand at once why all of Zoro's effects and clothing were ripped apart. The thin fin part of the tail-Zoro's tail, is almost translucent and curls on the floor as Zoro's tail is longer than his legs were.
Sanji's legs give out and he falls on his ass, a fact that thankfully goes unnoticed through the hubbub of excitement and intrigue from the rest of his nakama. Some kind of self preservation instinct kicks in and his legs suddenly find both the strength to support him again and the ability to get the hell out of there very quickly. He speeds past the ladies, not even sparing them a look, he's run three blocks before he dares stop.
Cautiously he pulls his hand from his face, his palm is positively coated in blood. He's no idea how he can have such a forceful nosebleed when so much of his blood seems to be currently concentrated in his cock. This shouldn't be happening, not over Zoro of all people. But fuck… that tail. The firm play of steely muscles under glittering scales, the ever appealing balance of strength and grace in that tail. He grinds his forehead against the brick wall and desperately forces down the urge to jerk off in public.
He manages to find his way back to the ship later, and when questioned by the others he lies and said that he ran off to try to find the girl that was clearly responsible for Zoro's… change. He actually manages to keep his shit together until he sees Zoro sprawled shamelessly across the deck arguing with Usopp, his tail shining temptingly in the sun.
"No, I can't kneel, Usopp. I don't have any fucking knees!" Zoro snarls angrily, as his tail twitches irritably.
"But can't you just balance on it? I'm sure they can do that." Usopp frowns gesturing vaguely to Zoro's… Zoro's… oh god. Sanji squeezes his eyes shut and focuses on breathing evenly. He can deal with this, it's just Zoro.
"How about I cut you in half and see how well you balance on your spine!" Zoro threatens.
"If you can't sit up what're you gonna do? Stab my ankles?" Usopp grins tauntingly. Sanji opens his eyes cautiously to see Zoro leaning forward, he's shirtless now, but at this angle Sanji can see that Zoro apparently has a thin dorsal fin starting at his tail bone. He watches in horrified arousal as it flicks irritably at Usopp's words, the movement apparently unconscious.
Zoro unsheathes his sword lightning fast and Sanji can just hear the squeak of fear from Usopp as the blade hovers threateningly at Usopp's crotch.
"I can reach a little higher than that." Zoro threatens darkly. After a second the swordsman pales suddenly and sways dangerously, causing Usopp to leap back or become a eunuch.
"I don't… feel so good." Zoro groans, his dorsal fin fluttering weakly.
Oh fuck. Sanji's starting to feel light headed, he needs to get out of here now. There's only so much he can look at Zoro when he's like that without either embarrassing himself or doing something hideously inappropriate. He squeaks some excuse and dashes out of sight into the aquarium room, which, in hindsight was probably not the wisest of choices given what drove him down here in the first place. But the room is dark and quiet and solitary, which is just what he needs now.
He sits down shakily on the bench with his back to the glass and manages to keep his hands steady long enough to light a cigarette. He inhales a calming hit of nicotine and tries to focus.
He's always had a thing for mermaids, even before he knew what sex was he knew that he wanted it with mermaids. They were just so graceful and beautiful, it was that contrast of beauty and power as well as the inherent danger of the ocean. All of that rolled up into one body made them irresistible, he could see why there were legends of them tempting sailors to their watery deaths.
So, he had a thing for mermaids, a fetish if you will. Apparently with Zoro's… change, it's a category that now includes him too. But that didn't mean that Sanji has a thing for Zoro at all, it's just… an unfortunately overlap of a fetish. After all, there were people who got hard from being handcuffed, Sanji would bet that that could get awkward if those people ever got arrested. It was just an unfortunate bleed over was all, it meant nothing. Nothing.
He was just going to go out there later, keep his shit together and remember that this was ZORO for goodness sake and get over it. He couldn't let Zoro know or he'd never hear the end of it. He can do this.
Light streams down from above and Sanji realises distantly that the lid to the aquarium has been lifted for some reason. He hears distant voices. He thinks he hears Chopper say something like 'dehydration' and 'rum' and Zoro yelling incoherently in protest of something or other. He's about to go back to smoking his cigarette when a loud splash and a mass of bubbles tears through the middle of the aquarium. In a second the bubbles clear to reveal Zoro, tail and all, floating in the aquarium desperately curled in on himself, clutching his hands over his mouth.
Sanji's cigarette falls from his open mouth as Zoro writhes in the water before him until he eventually gives in and opens his mouth, a massive stream of air bubbles escaping his lips. He watches in distant fascination as Zoro inhales on reflex and doesn't drown, Zoro looks a lot more surprised at that than Sanji is. He knows that mer-people can breathe underwater, it's obvious, but he's always wondered how they switch from breathing air to water, and now he knows. Zoro breathes experimentally, his tail swishing underneath him absently.
Sanji realises that he's got to escape before Zoro sees him, he's rock hard from watching Zoro in the water and it'll only be a matter of time before Zoro spots him. That is until it occurs to him that Zoro's inside the tank, and he knows from experience cleaning the tanks on the Baratie that if you're inside a water filled tank the walls look like mirrors, so Zoro can't see him unless Sanji gets real close to the glass or touches it. He's safe where he is.
Elated at his somewhat secure voyeurism he watches excitedly as the swordsman's tail properly unfurls in the water. The thin fin is something between green glass and silk underwater in its appearance. The patterning on Zoro's tail reminds Sanji a little of koi, if koi were green of course.
Zoro turns gracefully in the water and experimentally swims forward, the dorsal fin that Sanji spotted earlier properly unfolding and turning Zoro in the water on instinct. Sanji's mouth goes dry and he finds himself leaning against a pillar a little weak in the knees. Zoro is… gorgeous like this, so graceful and perfect. Zoro's body arcs in the water as he turns on himself to swim back the other way, his body more flexible than it's ever been, his expression is one of unfettered joy as a ripple runs through his spine and down his tail as he swims. Sanji knows that it would only take a few strokes with his shaky hands to bring himself to completion right now, he's so far gone just watching Zoro. But he restrains himself. He's going to have a difficult enough time looking at Zoro now without masturbating over the man and anyway, he knows all too well that it wouldn't be just the one time that it'd happen if he gave in.
He forces himself to turn away from the now very occupied aquarium and to close his eyes and think unsexy things. He actually has to go as far as imagining Zeff in lingerie before his hard on will go away. He briskly strides away, not daring to look back and heads off to go make dinner.
He finds out second hand from Chopper that Zoro can't stay out of water for that long at the moment, and the dehydrating rum and sunshine didn't help. Apparently mer-people have to train themselves to stay fully out of water for any length of time. Zoro nearly passed out from dehydration before Franky recognised the signs and threw him in the aquarium, apparently having a fishman for an adoptive father gives a man some knowledge of dehydration in marine creatures. Sanji tries not to think of Zoro swimming weightlessly in the water just below Sanji's feet. Chopper also informs Sanji that Zoro can't eat meat now, in the same way that Sanji can't eat rocks, he's just not built for it now apparently.
Sanji manages a white knuckled conversation with Zoro through the open hatch of the aquarium when he delivers the swordsman his meat-free dinner. The crew are agreed in chasing down the pirates to return Zoro to his normal form, a plan that Sanji desperately agrees with, he can't stay around Zoro like this. Zoro also agrees strongly apparently, for a man who once tried to chop off his feet he seems convinced that one can't become the world's greatest swordsman with no legs and he's sure as hell not waiting until he's thirty to get his legs back.
Cleverly Sanji manages to avoid Zoro for a day or so and steadfastedly refuses to get himself off at all, not trusting himself not to spring thoughts of Zoro and his beautiful tail into his mind at the crucial moment. He doesn't need to associate Zoro with orgasms, Zoro might be oblivious but Sanji is fantastically bad at keeping his feelings for people a secret when he wants them and even Zoro isn't so dense as to not notice if Sanji gained a habit of jerking off to thoughts of Zoro. That would certainly complicate their relationship as nakama.
His attempts at evasion are unfortunately derailed when Franky insists that Sanji has to swim in the ocean with Zoro because it's a fantastic experience to see Zoro in the element that his body was made for. Sanji doesn't doubt that one bit but refuses. Nami soaked to the skin in a bikini with a snorkel mask around her neck manages to convince him, he can't say no to Nami fully clothed, much less almost naked and dripping with water.
This is what leads him to find himself in the open ocean with a snorkel mask on and hating his life. He keeps a wary eye out for sea-kings but the ocean is endlessly deep below him and apparently empty, he's just beginning to think that Zoro isn't even there when he catches the flash of light off of scales to his right. Zoro is coasting lazily through the water, every so often a ripple of muscle down his body swishes his tail enough to keep him propelled forward. On impulse Zoro darts quickly down in the water and arcs his body up in a tight circle and quickly grasps the end of his own long tail apparently amused by his newfound flexibility.
Sanji cringes in the water, despite the cold he's already hard and Zoro's effortless grace in the water is pooling heat dangerously in the bottom of his spine. He hopes to god that the looseness of his swimming shorts will hide his state. Zoro apparently catches sight of him and grins as he swims over quickly. Sanji swallows nervously and tries to keep his face neutral around the snorkel and mask. Zoro starts speaking and Sanji is stunned to realise that he can hear him underwater as clearly as he could on the surface.
"You know," Zoro says as he swims lazily under Sanji, facing up so that Sanji gets a good long look at Zoro's tightly defined abs as well as the fascinating line where skin becomes scale. Sanji's entire body is humming with want and he only just manages to restrain himself from reaching out and touching Zoro's glorious form. He's certain that his face must be scarlet from embarrassment and lust, but if Zoro sees he doesn't mention it.
"if it weren't for me having to get back to normal to fight Mihawk I'd almost be tempted to stay like this. It's so fun." Zoro grins and bats his tail again, the movement edging Zoro's torso closer to him. Sanji bites down hard on the snorkel, glad that he's not expected to reply because he sure as hell wouldn't be able to say anything other than 'fuck me' to Zoro right now. He really needs Zoro to go because he's not going to be able to restrain himself any more with Zoro looking like that and being close enough to touch. He's seconds away from just cracking, grabbing Zoro and rubbing himself all over the other man until he comes.
"Well, whatever. See ya." Zoro shrugs, apparently bored with their one sided conversation.
Sanji breathes a shuddery sigh of relief as Zoro rolls in the water so he's swimming normally. Zoro's leaving, he's going to be okay.
Zoro dives and to Sanji's horror he can see Zoro's tail coming close to him, too close. Zoro's tail connects with his thigh and rapidly rushes higher, pressing against Sanji's hardness. God, it's all too much. He can feel Zoro's scales sliding slickly against his bare skin, he can feel the taut press of hard muscles just below them and by the time Zoro's thin translucent fin has ghosted over his crotch and his bare chest he's already curling in on himself and coming harder than he ever has in his life.
Terror washes over him but Zoro is already disappearing obliviously into the deeper darker water below them. He's not been caught, thank god. He shudders deeply and knows with certainty that the sensation of Zoro on him is going to be the only thing in his fantasies now for like forever. He is so screwed. Feeling at least partially thankful that the cold water has washed away all evidence of his lapse in control he slowly climbs back aboard, managing to viciously throw the snorkel and mask at Franky's head vindictively as he stalks back into the kitchen.
He manages to stay alone for the next day, without Zoro or anyone else asking him about his sudden 'problem' with Zoro. Nami informs him that evening that they're catching up to the ship that the pirates who changed Zoro are on. With keen sailing from her and a strategic use of the cola cannon that Franky built in they catch up before nightfall. Sanji feels inconceivably pleased about this, at last he can look at Zoro without feeling the impulse to rub himself on every inch of the man, without suffering embarrassingly sudden hard-ons and without having his ability to form coherent sentences vanish.
He steps out on deck prepared for a fight but the pirates have realised that with Usopp, Franky and Nami's weapons levelled threateningly at them as well as grappling hooks holding their ships together that they're outnumbered and outclassed.
"Change him back." Luffy orders their captain, his voice dangerously stern, the kind of voice Luffy gives warnings in before getting serious.
The brown haired woman steps forward sulkily at her own captain's silent command. Sanji glances down to Zoro who is propped up on his elbows on deck with his tail sprawled out beneath him, curled and shining in the dying light of the evening. Sanji gulps and averts his eyes. The woman walks angrily over to Zoro, her eyes narrowed dangerously at him, but Zoro's armed and his nakama are watching him carefully, weapons readied just in case. He holds his breath as she comes close to Zoro, this whole mer-thing will be over in just a second and he can stop being attracted to Zoro. It's just because of the tail, it's not a Zoro thing.
"Fine, I'll put you back how you were, every bit as irritating." She growls and pushes her hand to Zoro's chest. There's a bang of displaced air that sends Zoro flying back past Sanji and into the wall, bringing back an eerie sense of déjà vu. The dust clears and Sanji is so happy that he could dance for joy, Zoro has feet! No tail at all! Just his usual tanned feet with those stupid scars on his ankles! Of course Zoro is as a consequence completely naked and… sprawled temptingly across the deck, splaying his legs in oblivious joy at not having a tail anymore. Zoro looks… he looks like Christmas morning, all gloriously new and full of promise and just for him. Sanji is struck by the dual sensations of his stomach sinking in disappointment and his trousers tightening with interest.
So. Not a mer-thing then. Just a Zoro-thing.