Is it another woman? Usually is.
5 seconds sound clip from the McLintock! (1963) movie soundboard.
You can hear this line at 01:17:52 in the Blu-ray version of the movie.
Quote context
[...]
- Why did you and Mama stop living together, Daddy? Why did you separate?
- Aren't you going to answer me?
- It's sort of my business, I think...
- I don't.
- Is it another woman? Usually is.
- At your age, you always know what's usual...
- The first time I ever saw Mrs. Warren was last week.
- She has a job here at which she's very good...
[...]