Once, when Sanji was shopping, he found an apron that said "Kiss the Cook". Now, while he knew subconsciously that Nami-san would never fall for it, a more devious part of his brain whispered that it couldn't hurt to try. So he bought it, because if nothing else, what could it hurt?
What it could hurt turned out to be Sanji's pride – and face. He turned the oven burner up to 'high' and set the apron ablaze while Nami explained to their captain (calmly, rationally and with barely-stifled giggles) that some written instructions were not meant to be taken literally.