You’ve activated my trap card: infodumping my thoughts about Sanji’s fucked up relationship with vulnerability and intimacy.
I remember reading something once that talked about how many men struggle with discerning the difference between the desire for intimacy and the desire for sexual satisfaction because the two are so often considered synonymous for men in society. One person talked about how her partner thought he had ED issues until they started exploring different ways to fulfill his emotional needs and he learned the difference between being horny and wanting emotional closeness. That’s always kind of stuck with me, the way men are expected to fulfill all of their emotional needs through sex with romantic partners, because wanting non-sexual intimacy is something seen as “girly” or “weak.” And I’ve thought about it a lot in regards to Sanji and his relationship to masculinity and vulnerability.
Sanji has a very hard time expressing his kind and vulnerable side because of the abuse he suffered as a kid. After he ran away from Germa, he learned to act like a tough little asshole as a defense mechanism, because there was no one to protect him anymore. Even after Zeff took him in as someone who genuinely loves him, Zeff basically acts the same way, being rough and tumble ex-pirate who communicates his love to Sanji in more subtle ways. So being raised by him pretty much reinforced that switch in his personality to only showing his kindness in ways that are considered acceptable for a man (cooking, flirting with women, ect.)
Sanji is most comfortable putting on a tough guy persona and acting like an asshole, even if his actions directly contradict it (e.g. saying he only saves women only to risk his life throwing Usopp out of danger three seconds later). Which is something a lot of people in One Piece do, but Sanji takes it to another level, because even now he has his family’s voices in the back of his head telling him he’s weak, a failure, subhuman. Rather than just a front to act tough, I think Sanji genuinely feels unsafe showing the parts of himself he was told make him weak. He trusts his friends with his life, but childhood trauma dies hard and the traumatized child inside him still thinks showing kindness and vulnerability leads to pain, and as such he still struggles to be truly emotionally vulnerable with people, ESPECIALLY other men, who he sees as the bigger threat.
However, fearing your emotional needs doesn’t make them go away. Sanji LOVES people. Despite his incurable asshole disease, he’s extremely personable. He has a big bleeding heart and cares so deeply for the people around him. He craves connection, and I think that goes doubly so for a romantic relationship, because Sanji loves so intensely. I think in a relationship with Zoro they would have a hard time getting into sync at first. Falling in love with Zoro came out of LEFT FIELD for Sanji, it was in NO WAY something he was prepared for and is nothing like he ever imagined, therefore it’s completely uncharted territory. They suck at communicating because Zoro doesn't always realize things need to be said out loud and Sanji’s afraid to ask. He’s especially not comfortable with the idea of wanting intimacy from Zoro. Despite the inherent trust and respect they have for each other, their relationship has always been volatile, electric, violent. There’s no room for softness. Men aren’t supposed to want tenderness from other men. He’s not supposed to want closeness from Zoro. That’s not how they are, that’s not what he pretends he is.
Sex on the other hand, sex is safe. Men are supposed to want sex—expected to—and while sex and emotional intimacy often go hand in hand it’s not scoffed at the way non-sexual intimacy is. He’s able to fulfill some of the desire for closeness through sex without completely opening himself up to vulnerability. But wanting sex and wanting intimacy aren’t the same thing, and Sanji’s not actually allowing himself what he needs. Enter Zoro figuring out what Sanji’s doing after he reaches a breaking point (starts sobbing half-way through sex which PANICS THE HELL out of Zoro) and being like “yeah I’m not letting him do that anymore” and starts opening up the option for different kinds of intimacy in their relationship in a way that doesn’t make Sanji feel exposed or demeaned.