Buck Privates (1941)
Slicker Smith: You're 40 years-old and you're in love with this little girl that's 10 years-old. You're four times as old as that girl and you couldn't marry her, could you?
Herbie Brown: Not unless I come from the mountains.
Slicker Smith: All right- you're 40 years-old, you're four times as old as this girl, and you can't marry her, so you wait five years. By that time the little girl's 15 and you're 45. You're only three times as old as that little girl. So you wait 15 years and when the girl is 30, you're at 60. You're only twice as old as that little girl.
Herbie Brown: She's catching up.
Slicker Smith: Yes, yes. Now here's the question. How long do you have to wait until you and that little girl are the same age?
Herbie Brown: Now what kinda question is that? That's ridiculous!
Slicker Smith: Ridiculous or not, answer the question.
Herbie Brown: If I wait for that girl she'll pass me up. She'll wind up older than I am.
Slicker Smith: What are you talking about?
Herbie Brown: She'll have to wait for me!
Slicker Smith: Why should she wait for you?
Herbie Brown: ...I was nice enough to wait for her!
Slicker Smith: Throw your chest out! Go on! Throw your chest out!
Herbie Brown: I'm not through with it yet!
Slicker Smith: Quiet!
Herbie Brown: What time is it?
Slicker Smith: None of your business!
[completely ad-libbed during the drill routine. Abbott didn't know it was coming but delivered his response flawlessly]