CHRIS: The overrides are biometrically linked to me.

DOCTOR: So I’d need a sample of your DNA to trip the lock. Right! You know what you need to do.

CHRIS: Oh, all right, fine. I’ll kiss you.

(Mwah! Chris kisses the Doctor.)

DOCTOR: Oh. No, I just meant a follicle of your hair.

CHRIS: Oh. Really?

DOCTOR: But don’t worry about it.

CHRIS: Oh, I’m so embarrassed.

DOCTOR: There should be enough on my lips, um—oh, actually I probably need a bit extra. Hang on.

(Mmmmwah! The Doctor kisses Chris back.)