"I can't have sex with you. It's taking advantage of you because you don't want to have sex."
"It is not, I want to have sex with you because you want to have sex."
"Well that doesn't make any sense."
"Sure it does, I want you happy because then I'm happy. Just because I don't have much of an interest in sex for myself, I'm all for it if it makes you happy, John."
"Sherlock, don't be ridiculous. I'm not going to force you into something you don't like."
"It's not a question of like. It's like…when I actually get milk to make you happy."
"So sex with me would be like getting the milk?"
"No, come now, follow along. It's logic, that's all."
"I don't want you using your logic on me."
"Can't shut it off. And anyway, if you're happy you make tea. I like tea."
"So sex is tea now?"
"Well, sex leads to tea."
"You'll have sex with me so that I am happy and I make you tea, then?"
"Yes… well all right then."
"No, bit not good really, but I can't work around your logic."