Quote from Frasier in Don Juan in Hell (Part 2)
Bob: So how do you know Kirby? Frasier: Well, I was his, uh, tutor. Bob: Yow. How much do I owe you for that? Frasier: It was a pleasure really. So you're Kirby's dad? Lana's ex who ran off with the dental hygienist. Bob: ... But you can call me Bob.