Well, my, my, there's a little bit of the devil in you, isn't there, young man? Ha, ha.
8 seconds sound clip from Batman (1966) - The Cat's Meow (S2E29) TV Series.
You can hear this line at 00:18:41 in the Blu-ray version of the movie.
Quote context
[...]
- Well, how could I forget a thing... Of course, what can I do for you, Robin?
- We're here to see Ms. Klutz, she's one of your dance instructors.
- Oh, yeah, well, I'm afraid that's impossible right now.
- Just tell her Batman and Robin are here. And tell her fast.
- Well, my, my, there's a little bit of the devil in you, isn't there, young man? Ha, ha.
- Just as I suspected, Robin, she's up to her old tricks.
- A bit of whimsy that escapes me at the moment, Batman. Get him, guys.
- You know something? Hm? If he weren't such an old stick in the mud, I might let him live.
[...]