Luffy has tried a cigarette all of once.
He tried going after Dadan's once or twice but Sabo (with encouraging from Ace) carefully put that to rest. Dadan just kicked him in the head and cited that it was too expensive to share with a brat like him.
When he asks years later, on the deck of a ship oceans away from that mountain bandit's home rolled brand, Sanji just looks at him carefully before slowly asking "Why?"
Luffy shrugs, not taking his eyes off the smoldering end that glowed brightly in the dark. "I dunno. They smell gross, but you like them so they must taste pretty great."
Sanji huffs a laugh, quiet in the night air, before taking another drag, the burning tip glowing more furiously for a second. He doesn't say anything for a while as he looks out to sea, holding in the nicotine air for a long time before letting it out slowly. Luffy has learned over the years to stop scrunching up his face at the smell, even learning to tolerate certain brands (like Sanji's) over others. He still tries not to breathe in too deeply as the smoke drifts past him on the wind and instead watches the slow grin that creeps across his crew mate's face.
"Don't you know..." the cook starts slowly, holding the cigarette close to his grinning mouth, "That smoking weakens your taste buds? What will you do if you can't appreciate the taste of meat anymore?"
Luffy frowns. That certainly was a problem. "It'll be okay right? You'll just make everything tastier if that happens!"
Sanji laughs louder this time. Then sighs. "That stupid marimo will never forgive me," he grumbles. He lets his voice change to a breathy whisper, "And I would never be able to look Nami-san or Robin-chan in the eye again."
Luffy laughs along with him. "What about Chopper?"
There's a groan as Sanji half-slumps over the rail of the deck. "No, no. Don't make me think about his disappointed face. It'll haunt me till the end of my days."
Luffy giggles as Sanji grins around his cigarette which is burning ever shorter. He pouts as Sanji quietly flicks the ash into the dark waters below.
"Pleeeaaase?" he whines. "You share with Brook!"
Sanji sighs again, looking vaguely annoyed. "You're not going to give up on this," he states more than asks. He takes another drag and pins Luffy with a small glare. "And Brook has smoked before, so it's not like I'm helping corrupt anything, even if he doesn't have lungs or taste buds for that."
They both automatically chime "skull joke" to no one in particular.
The cigarette is now a stub and Sanji flicks it into the ocean where its glow is lost forever before walking off to the galley.
Luffy stands there pouting at the dark waves where he last saw the glowing stub before turning his attention back to his cook when he calls out to him.
He stands in the light of the galley, leaning against the door. "Well, come on. I'll give you a snack when you end up coughing your lungs out."
The captain is there in no time at all, a whirlwind of rubber limbs that almost crashes violently into him, before landing in his reserved seat.
Sanji sits next to him, placing an ashtray between them, and Luffy nearly stops fidgeting in excitement to analyze how strange that looks. It's odd to see the cook sitting, slightly hunched over the table instead of standing over hungry crew mates, pacing between the kitchen and the dining table, or leaning against the wall to take a breather. The blond flicks a lighter open, cupping a hand around the cigarette and the flame, taking a drag for himself before delicately handing it to Luffy.
"Just take it easy, okay?" is all he says as he reluctantly gives it up.
Luffy isn't sure what he expected. It's hot smoke in his mouth and down his throat and he takes it all in for as long as he can as his eyes water painfully and his mouth dries up. He hacks it up and he can't stop coughing even when Sanji snatches the stick out of his hand and shoves a glass of water at him.
"Alright, alright!" There's an edge to Sanji's voice, but he gently rubs his captain's back and says "Just try to breathe slowly. And drink the water when you can."
Luffy does so, his mouth feeling strangely dry and slight grit in the taste. There's a burn in his throat and it tingles. He eyes the still-lit cigarette that Sanji's keeping away from him, but Sanji shakes his head and stubs it out in the ashtray.
"That's enough for now," is all he says before he moves to kitchen proper. "How about... an omelet since it's early morning anyway?"
Luffy hums a response but continues to look at the ashtray.
His mouth feels dry and his eyes are stinging from the smoke. He wants to try it again because he remembers the way the smoke burned in his throat almost pleasantly before it got mangled by the coughing.
He rolls the slightly used cigarette around in his fingers, positioning them in all the ways he's seen it held, pretending to suck in another breath even though it's nothing like before.
Sanji carefully slides a full plate in front of him and he's got-he's got this look on his face, the one that Nami or Chopper get when they've pushed themselves to hard in a fight. Or how Zoro looks when he's far gone in his training. Or how Robin used to look at them sometimes, gaze drifting off to the ocean behind them.
Luffy apologizes by shoving the entire omelette into his mouth at once.
"Would you stop eating like a pig?" Sanji snaps, but there's no bite to it, present look or not.
"It's good!" Luffy cheers around the food, hand coming up to keep it all in. He pauses for a second, sniffing, then swallowing the omelette down slowly, hand still resting in front of his face.
"What?" his cook asks warily. He keeps his body relaxed as he leans against the table staring down at him, but he's got that look again.
Luffy breathes in deeply, hand pressed against his nose. "I smell like you," he says after a while. "It's nice."
Sanji sighs, but it sounds oddly relieved and a little exasperated. He picks up the slightly rumpled cigarette that Luffy abandoned by the ashtray and lights it up again.
Luffy breathes in the scent of his hands again, carefully licking down his teeth for remaining omelette. He smells like Sanji or the galley after a meal because Sanji never smokes while others eat or nine in the morning or two in the aftenoon on the deck or-
Sanji's long legs brush against Luffy's as he unfolds them under the table. He's sitting to the right of him just as before, relaxed back in his chair and head tilted up the ceiling, smoke delicately billowing out between pursed lips.
Or cool late nights out on the sea.