Disclaimer: I don't own Sherlock. I can dream, though.
John: I'm going to be a bit late at getting to the morgue. I'm going out with Lestraude. -JW
Sherlock: Ok. Don't be too naughty, John. -SH
John: Oh, God. You know what I meant, Sherlock. -JW
Sherlock: I thought you were dating that boring teacher. -SH
Obviously, you've broken up. -SH
John: Sherlock. I can't even get away with a stupid miswording! -JW
Sherlock: Oh, John? -SH
John: What? -JW
Sherlock: I really hope, for your sake, Mycroft doesn't know about you and Lestraude. -SH
John: SHERLOCK!