Spike: Who the hell is this?!
Buffy: It’s your lucky day, Spike.
Kendra: Two Slayers!
Buffy: No waiting!
Buffy the Vampire Slayer, Season 2: Episode 10 – “What’s My Line, Part 2”
Xander: As long as nothing really bad happens between now and then, you’ll be fine.
Buffy: Are you crazy? What did you say that for? Now something bad is gonna happen!
Xander: Whadaya mean? Nothing’s gonna happen.
Willow: Not until some dummy says, ‘as long as nothing bad happens.’
Buffy: It’s the ultimate jinx!
Willow: What were you thinking? Or were you even thinking at all?
Xander: Well, you guys don’t know. Maybe this time it’ll be different.
Buffy the Vampire Slayer, Season 2: Episode 3 – “School Hard”

Buffy the Vampire Slayer, Season 4: Episode 8 – “Pangs”
Spike: A bear! You made a bear!
Buffy: I didn’t mean to!
Spike: Undo it! Undo it!