(A waitress walks up behind Frasier)
Frasier: It's a mean-spirited thought! Marie is not using me. She would want me just as much even if I weren't a psychiatrist. You know, you're jealous! You're jealous that I'm having sex! Jealous that I'm having hot, passionate, sweaty jungle sex! What are you having?!
Niles: (to the stunned waitress) I'm having a latte.