Xander: Willow, did you remember to tape Biography last Friday? 

Willow: Uh-huh.

Buffy: See, I told you. Old Reliable.

Willow: Oh, thanks. 

Buffy: What? 

Willow: ‘Old Reliable’? Yeah, great. There’s a sexy nickname. 

Buffy: Well, I-I didn’t mean it as… 

Willow: No, it’s fine. I’m ‘Old Reliable’. 

Xander: She just means, you know, the geyser. You’re like a geyser of fun that goes off at regular intervals. 

Willow: That’s Old Faithful. 

Xander: Isn’t that the dog that, that the guy had to shoot…

Willow: That’s Old Yeller.

Buffy: Xander, I beg you not to help me.

Buffy the Vampire Slayer — Season 3: Episode 16 — “Dopplegangland”