Well, prove it.
3 seconds sound clip from the Mister Ed movie soundboard.
You can hear this line at 00:09:46 in the DVD version of the movie.
Quote context
[...]
- Yeah, but he winked at me first.
- Look, there is nothing wrong with that horse. Look.
- Come in. Aren't you people overdoing this a bit?
- She's letting me keep the horse.
- If I were you, I'd keep my door closed.
[...]