Zoro is confident in saying that Sanji is a man who doesn’t do what he’s told. Which is why, when a command accidentally slips from Zoro’s lips during foreplay, he is expecting to hear the cook’s scoff as he continues to do what he pleases.

“So, we’re gonna play it like that, huh, Cook?” “Oh yeah. We’re gonna play it like that,” Sanji returns, despite having absolutely no fucking clue what Zoro could possibly mean by that. --- Or: The Great Game of Gay Chicken Aboard the Thousand Sunny

Sanji will just go knock. Appease his own sense of responsibility, get yelled off, and come back to his own bed knowing he tried. It’s the least he owes the frustrating marimo, as crewmates; to at least make sure he’s got options.