Oh MAAAAAAAN.... Zoro, Zoro, Zoro. Where does Sanji begin with you?
You're nakama. You were and will ALWAYS be nakama. Meaning, you're crew, you're a friend, you're family. We may bicker and fight, but Sanji will always have your back. He knows he can trust you with everything. He might not admit it, but he has a great deal of respect for you. He's impressed by your loyalty to Luffy and the rest of the crew. He admires - and is slightly jealous of - your dedication and your strength. He's also a little jealous of your "totally manly body", because you so represent the classic 'male physical ideal'... and - headcanoning - when he was younger, he was always teased about being a skinny, lanky shrimp, and as much as he trains, he just never can seem to pack on the same amount of muscle mass (his fighting style wouldn't allow for it, anyway), so... yeah. There's a bit of that. XD;; He appreciates that you're always looking out for the other crew members, and will do anything to protect them, so he knows he doesn't have to worry about any of the crew, when you're with them. He probably won't say as much to you directly... not wanting to over-inflate your ego, and all. ;3
You drive him absolutely around the bend, and up the wall... with your total lack of direction, and the way you always seem to know exactly what to say, or do, to irritate him. You manage to push all of his buttons so well. You piss him off so easily, at times. That said, Sanji has found that he actually has come to enjoy most of the bickering pot-shots they take at each other, and has fun with the "fighting" (read: sparring) matches. He knows he can really let loose against Zoro, that he can't against any of the other members of the crew. Perhaps Luffy, but Luffy wouldn't be as interested in fighting like this, seeing it instead as just something light and amusing, and wouldn't push him. Zoro will really push Sanji, and Sanji will push back... he knows they can go at each other as strong as they'd like, but neither of them would intentionally hurt the other, either. He trusts Zoro's control. So fighting with Zoro is a great way to keep in practice. And, sometimes, it really can be fun to just push himself to the limit, let himself go, and all that. The verbal bickering can be fun, too... Sanji always tries to get one-up on Zoro, verbally and mentally. The insults are more teasing, and a game of wits. Sometimes the fights are more serious... tempers flaring hot and things not as fun. When Sanji's temper is getting the better of him, it's either because he's feeling rather insecure at the moment, or Zoro (or someone) has managed to hit him in a more (emotionally/mentally) vulnerable place, and he doesn't want to admit to that... or something serious has happened, and Sanji is deeply concerned for Zoro, and the only way he knows how to show that concern is to yell/tease/nag.
Here in Nautilus? OMG... have things gone complicated, and crazy. At first, Sanji was afraid for ANY of his nakama to show up in Nautilus, because he feared their reactions to this place, and what it meant for their dreams. Knowing how DEEPLY all his crew are to their dreams, how much their dreams mean to them... most (not all) have no real meaning here in Nautilus, or are unobtainable here. Sanji DID NOT want to see how his nakama react to that knowledge. He had supressed his dream before, for Zeff, and the Baratie... so he could do it again. He could survive, if it meant no others of his nakama came here. So when Zoro first arrived, Sanji was scared. He didn't know how Zoro would react, how hurt/disillusioned/hateful he might be of the place, if his goal of becoming the world's greatest swordsman meant nothing in this place. But Sanji had also been terribly LONELY, here in Nautilus, too. Sanji had made a bunch of casual accquaintances, and some closer friends, but not many. Sanji tended to keep people at a polite distance; being friendly, but not offering too much of himself, or his past. It takes a lot to earn Sanji's trust, and to become a close friend to him. His friends were his nakama, and he missed them. So, despite being afraid, he was also so thrilled, and joyous, to finally have at least ONE of his nakama here with him, now. Even if it WAS the annoying guy he fought with all the time.
Thanks to Some. Certain. Storms things have gotten... awkward between the two. To say the least. Sanji always believes himself to be a total ladies man, born to love the ladies, and nothing BUT the ladies. Which is why - at the current time - he can't even comprehend that there is a slowly-growing attraction to Zoro, here. It's in its infancy, Sanji does not realize what he's feeling, and is in total denial about it... but there's a seed there, at least. To go with everything mentioned above... Sanji fully trusts Zoro... knows that when the chips are down, he can fully depend on him... has fun bickering and fighting with him at times... can (even if he doesn't realize it/can't say it) appreciate Zoro physically... and they're nakama. They're close. Sanji may be a lot further back in time than Zoro, back in their home world... but he's still fought shoulder-to-shoulder, back-to-back with the guy, and knows he can trust him implicitly. Hindering things, is that Sanji has A LOT of "manly pride". He grew up on a ship FULL of ruffians and ex-pirates, of course. No doubt - headcanoning - that there was a lot of teasing about "pretty boys", and "cabin boys", and the like. Sanji has some very clear ideas in his head as to what it means to "be a man", especially as it pertains to him. He'd always struggled to grow up fast, and be seen as a "man", growing up on the Baratie. Since arriving in Nautilus, and meeting some of the people here... some of the guys who like guys... and especially finding out that Ace, and his own nakama prefer guys, well... Sanji's accepting of that. It's their business, it's 'love'... and so long as guys didn't come on to him, he didn't care what they did; that was their business. His upbringing/way of thinking right now, though, won't allow himself to accept that - yes - he just might be interested in guys as well. Sanji will stubbornly say he's not gay, and he isn't gay. Sanji will ALWAYS love the ladies, admire their beauty, and fawn over them... but he's too afraid/too stubborn/it's still too early for him to realize that he's actually just slightly bi. The percentage is low, Sanji will not be interested in most guys, but Zoro just is happening to fall into that, say... 1 or 2% that Sanji could lean towards, that way. It's still a ways off from him accepting that information about himself, though. He's still pretty much unaware/in denial that this is even happening (Sanji SOOOOOO needs to get dunked in the Nile, at some point. Probably the moment he REALIZES he's actually in denial about these things). It'll take some time, and a LOT of personal insight/debating/change/what-have-you before Sanji comes to terms with his new, confused, growing feelings. IF it happens at all. (eta: He knows he's "involved" with Ace, though... so even if/when he does realize what he's starting to feel, he probably won't act on it. Pride, stunned that he'd ever FEEL that way about Zoro, and he really doesn't want to interject into other people's relationships. For as much as he flirts and fawns, he DOES respect people's feelings, and love, so he'll back off if people are in relationships.)
So... yeah. TL;DR? Sanji's thoughts on Zoro are complex. X3 But also simple, at the same time. They're nakama, and as much as they annoy and aggrivate each other, he knows that they'll also always be there for each other, too.
INCOMING ESSAY!
You're nakama. You were and will ALWAYS be nakama. Meaning, you're crew, you're a friend, you're family. We may bicker and fight, but Sanji will always have your back. He knows he can trust you with everything. He might not admit it, but he has a great deal of respect for you. He's impressed by your loyalty to Luffy and the rest of the crew. He admires - and is slightly jealous of - your dedication and your strength. He's also a little jealous of your "totally manly body", because you so represent the classic 'male physical ideal'... and - headcanoning - when he was younger, he was always teased about being a skinny, lanky shrimp, and as much as he trains, he just never can seem to pack on the same amount of muscle mass (his fighting style wouldn't allow for it, anyway), so... yeah. There's a bit of that. XD;; He appreciates that you're always looking out for the other crew members, and will do anything to protect them, so he knows he doesn't have to worry about any of the crew, when you're with them. He probably won't say as much to you directly... not wanting to over-inflate your ego, and all. ;3
You drive him absolutely around the bend, and up the wall... with your total lack of direction, and the way you always seem to know exactly what to say, or do, to irritate him. You manage to push all of his buttons so well. You piss him off so easily, at times. That said, Sanji has found that he actually has come to enjoy most of the bickering pot-shots they take at each other, and has fun with the "fighting" (read: sparring) matches. He knows he can really let loose against Zoro, that he can't against any of the other members of the crew. Perhaps Luffy, but Luffy wouldn't be as interested in fighting like this, seeing it instead as just something light and amusing, and wouldn't push him. Zoro will really push Sanji, and Sanji will push back... he knows they can go at each other as strong as they'd like, but neither of them would intentionally hurt the other, either. He trusts Zoro's control. So fighting with Zoro is a great way to keep in practice. And, sometimes, it really can be fun to just push himself to the limit, let himself go, and all that. The verbal bickering can be fun, too... Sanji always tries to get one-up on Zoro, verbally and mentally. The insults are more teasing, and a game of wits. Sometimes the fights are more serious... tempers flaring hot and things not as fun. When Sanji's temper is getting the better of him, it's either because he's feeling rather insecure at the moment, or Zoro (or someone) has managed to hit him in a more (emotionally/mentally) vulnerable place, and he doesn't want to admit to that... or something serious has happened, and Sanji is deeply concerned for Zoro, and the only way he knows how to show that concern is to yell/tease/nag.
Here in Nautilus? OMG... have things gone complicated, and crazy. At first, Sanji was afraid for ANY of his nakama to show up in Nautilus, because he feared their reactions to this place, and what it meant for their dreams. Knowing how DEEPLY all his crew are to their dreams, how much their dreams mean to them... most (not all) have no real meaning here in Nautilus, or are unobtainable here. Sanji DID NOT want to see how his nakama react to that knowledge. He had supressed his dream before, for Zeff, and the Baratie... so he could do it again. He could survive, if it meant no others of his nakama came here. So when Zoro first arrived, Sanji was scared. He didn't know how Zoro would react, how hurt/disillusioned/hateful he might be of the place, if his goal of becoming the world's greatest swordsman meant nothing in this place. But Sanji had also been terribly LONELY, here in Nautilus, too. Sanji had made a bunch of casual accquaintances, and some closer friends, but not many. Sanji tended to keep people at a polite distance; being friendly, but not offering too much of himself, or his past. It takes a lot to earn Sanji's trust, and to become a close friend to him. His friends were his nakama, and he missed them. So, despite being afraid, he was also so thrilled, and joyous, to finally have at least ONE of his nakama here with him, now. Even if it WAS the annoying guy he fought with all the time.
Thanks to Some. Certain. Storms things have gotten... awkward between the two. To say the least. Sanji always believes himself to be a total ladies man, born to love the ladies, and nothing BUT the ladies. Which is why - at the current time - he can't even comprehend that there is a slowly-growing attraction to Zoro, here. It's in its infancy, Sanji does not realize what he's feeling, and is in total denial about it... but there's a seed there, at least. To go with everything mentioned above... Sanji fully trusts Zoro... knows that when the chips are down, he can fully depend on him... has fun bickering and fighting with him at times... can (even if he doesn't realize it/can't say it) appreciate Zoro physically... and they're nakama. They're close. Sanji may be a lot further back in time than Zoro, back in their home world... but he's still fought shoulder-to-shoulder, back-to-back with the guy, and knows he can trust him implicitly. Hindering things, is that Sanji has A LOT of "manly pride". He grew up on a ship FULL of ruffians and ex-pirates, of course. No doubt - headcanoning - that there was a lot of teasing about "pretty boys", and "cabin boys", and the like. Sanji has some very clear ideas in his head as to what it means to "be a man", especially as it pertains to him. He'd always struggled to grow up fast, and be seen as a "man", growing up on the Baratie. Since arriving in Nautilus, and meeting some of the people here... some of the guys who like guys... and especially finding out that Ace, and his own nakama prefer guys, well... Sanji's accepting of that. It's their business, it's 'love'... and so long as guys didn't come on to him, he didn't care what they did; that was their business. His upbringing/way of thinking right now, though, won't allow himself to accept that - yes - he just might be interested in guys as well. Sanji will stubbornly say he's not gay, and he isn't gay. Sanji will ALWAYS love the ladies, admire their beauty, and fawn over them... but he's too afraid/too stubborn/it's still too early for him to realize that he's actually just slightly bi. The percentage is low, Sanji will not be interested in most guys, but Zoro just is happening to fall into that, say... 1 or 2% that Sanji could lean towards, that way. It's still a ways off from him accepting that information about himself, though. He's still pretty much unaware/in denial that this is even happening (Sanji SOOOOOO needs to get dunked in the Nile, at some point. Probably the moment he REALIZES he's actually in denial about these things). It'll take some time, and a LOT of personal insight/debating/change/what-have-you before Sanji comes to terms with his new, confused, growing feelings. IF it happens at all. (eta: He knows he's "involved" with Ace, though... so even if/when he does realize what he's starting to feel, he probably won't act on it. Pride, stunned that he'd ever FEEL that way about Zoro, and he really doesn't want to interject into other people's relationships. For as much as he flirts and fawns, he DOES respect people's feelings, and love, so he'll back off if people are in relationships.)
So... yeah. TL;DR? Sanji's thoughts on Zoro are complex. X3 But also simple, at the same time. They're nakama, and as much as they annoy and aggrivate each other, he knows that they'll also always be there for each other, too.