By The Chichi Slaughter House
Warnings: Maybe OOC.
Disclaimer: I don't own One Piece and I make no money from this writing.
It's not that Sanji doesn't care for Zoro; it's that he knows he can take his kicks and still be fine. So he kicks. Aggravating him is the only way to touch him, so he lays the bait and accepts whatever comes his way.
Zoro knows this and that's why he bothers to fight back. He knows Sanji's behaviour towards women is just a front, and revels in the knowledge. But he won't act until Sanji does first. Breaking him down slowly seems more fun.
To see the shitty cook get flustered.
Or maybe it's because he would blush too.