Meredith Grey: Just for the record... you'd tell me if I need to get tested, right?
Derek Shepherd: You think I have syphilis?
Meredith Grey: No, I don't. It's just... We never made any rules or anything. I mean, we never said, "We have rules," and I wouldn't hold it against you.
Derek Shepherd: When would I have time to go out and get syphilis? You're a handful enough as it is, and besides, we're practically a condom ad.
Meredith Grey: But no more glow-in-the-dark ones.
Derek Shepherd: You see? There's nothing to worry about. Maybe we should, you know, make some rules, I mean.
Meredith Grey: We should.
Derek Shepherd: Just for the record... I like the glow-in-the-dark ones.