Reptile Boy (Season 2, Episode 17):

Sunnydale High School. Cut to the hall. Cordelia is demonstrating her fake laugh to another girl.

Cordelia: (fake laughter) See? Dr. Debi says when a man is speaking you make serious eye contact, and you really, really listen, and you laugh at everything he says. (laughs again)

Cut to the stairs. Willow and Buffy come down and head down the hall.

Willow: You dreamed about Angel again?

Buffy: Third night in a row.

Willow: What did he do in the dream?

Buffy: Stuff.

Willow: (smiles wide) Oh! Stuff! (Buffy smiles) Was it one of those vivid dreams where you could feel his lips and smell his hair?

Buffy: It had surroundsound. I'm just thinking about him so much lately.

Willow: You two are so right for each other. Except for the, uh...

Buffy: Vampire thing.

Willow: That doesn't make him a bad person. Necessarily.

Buffy: I'm brainsick. I can't have a relationship with him.

Willow: Not during the day, but you could ask him for coffee some night. It's the non-relationship drink of choice.

Xander comes out of a classroom, sees them and hurries to catch up.

Willow: It's not a date, it's a caffeinated beverage. Okay, sure, it's hot and bitter like a relationship that way, but...

Xander: What's like a relationship?

Buffy: Nothing I have. Coffee?

Xander: Huh?

He stops by Cordelia as Willow and Buffy get a drink at the fountain.