Spike: The last time I looked in on you two, you were fighting to the death. Now you’re back making googly-eyes at each other like nothing happened. Makes me want to heave.
Buffy: I don’t know what you’re talking about.
Spike: Oh, yeah. You’re just friends.
Angel: That’s right.
Spike: You’re not friends. You’ll never be friends. You’ll be in love till it kills you both. You’ll fight, and you’ll shag, and you’ll hate each other till it makes you quiver, but you’ll never be friends. Love isn’t brains, children, it’s blood… blood screaming inside you to work its will. I may be love’s bitch, but at least I’m man enough to admit it.
Buffy the Vampire Slayer — Season 3: Episode 8 — “Lovers Walk”