Diane: But this is quite a surprise. You've only known each other a few months, and you're moving in together? That's pretty impetuous.
Lilith: Well, a week ago, we decided to take a chance on cohabitation, but we waited a week before announcing the news, so as to avoid putting any undue pressure on the success or failure of the endeavor. And now we are pleased to announce the effort a limited success.
Diane: Yes, pretty darn impetuous.

Frasier: All right, uh, Diane and I were engaged to be married and she left me at the altar. The whole experience was so humiliating, l- l- I've just been trying to forget it ever since.
Lilith: Your feelings for her were genuine?
Frasier: Yes.
Lilith: And it's only on account of her action that you're not married to her at this very moment?
Frasier: Well, I- I never really looked at it that way.
Lilith: And if Sam were out of the picture, you'd throw me over and run back to her, wouldn't you?
Frasier: I don't love her anymore.
Lilith: You switch your passions on and off very quickly, Dr. Crane.
Frasier: I do not!
Lilith: Then you do still love her!
Frasier: Well, I never did!
Lilith: You were going to marry her!
Frasier: Well, maybe I just thought I loved her!
Lilith: How do I know you don't just think you love me?
Frasier: Well, I don't. I mean, I- I didn't I- I never... I will not be grilled like a common criminal! [slams the bathroom door]
Sam: [to Lilith] Cheese knife?

Frasier: Doctors Sternin and Crane are proud to announce that they are now officially POSSLQ's. [chuckles]
Lilith: It means "Persons of the Opposite Sex Sharing Living Quarters."
Frasier: Yes.
Diane: Oh.
Frasier: You see, it's a little, uh, lovers' in-joke we picked up from a Census Bureau acronym.
Woody: Oh, I love those.