Sherlock, Series 3

Mary Watson:
David, this is Sherlock.

David:
Yeah, we've, um...we've met.

[Flashback to Sherlock's living room, where he is apparently interviewing David]

David:
So, what exactly are my duties as an usher?

Sherlock Holmes:
Let's talk about Mary first.

David:
Sorry, what?

Sherlock Holmes:
Oh, I think you know what. You went out with her for two years.

David:
Er...ages ago, we're just good friends now.

Sherlock Holmes:
Is that a fact? Whenever she tweets, you respond within five minutes regardless of time or current location, suggesting you have her on text alert. In all your Facebook photos of the happy couple, Mary takes centre frame whereas John is always partly or entirely excluded.

David:
[Laughing nervously] You can't assume from that that I've still got...some kind of interest in Mary...

Sherlock Holmes:
You volunteered to be a shoulder to cry on on no less than three separate occasions. Do you have anything to say in your defence? [David looks stunned] I think from now on we'll downgrade you to 'casual acquaintance with no more than three planned social encounters a year, and always in John's presence'. I have your contact details. I will be monitoring.

David:
...They're right about you. You're a bloody psychopath.

Sherlock Holmes:
High-functioning sociopath. With your number. [He grins evilly]