Oh, you mustn't do this villainous thing.
5 seconds sound clip from the Wuthering Heights (1939)) classic radio play.
You can hear this line at 00:37:26 in the radio play.
Quote context
[...]
- Yes, you do love him. You're mad with pain and jealousy at the thought of my marrying him.
- Sit down, Cathy. I won't say I'm not surprised to see you.
- Heathcliff, is it true? Did you ask Isabella to marry you?
- Oh, you mustn't do this villainous thing.
- And that's what I intend to do.
- Yes! To teach you the ways of pain and the hell that I'm in.
[...]