Don't put the idea in her head.
3 seconds sound clip from the The Philadelphia Story movie soundboard.
You can hear this line at 00:05:11 in the Blu-ray version of the movie.
Quote context
[...]
- Yes, dear, I know. Now I have my self-respect and no husband.
- You almost talk as though you wanted him back.
- He wouldn't come back, probably.
- Is he handsome, or is he not?
- Really? Why don't you postpone the wedding?
- How?
- Don't put the idea in her head.
- He's waiting for us at the stables.
- Mother, if I don't choke her before Saturday...
- It'd postpone the wedding, wouldn't it?
- Be in the car when I get down.
[...]