What has kept you two? We were worried!
3 seconds sound clip from the Robot Monster (1953) movie soundboard.
You can hear this line at 00:46:54.521 in the Blu-ray version of the movie.
Quote context
[...]
- It's all right, boy. You did right.
- And Ro-Man won't find it easy to counteract the serum, so we have still a little time left.
- I only wish it were over now.
- Well, when it is, can I go over to Janie's house and borrow her dolls?
- What has kept you two? We were worried!
- Now, really, Father, isn't it obvious?
- Have you been playing house?
- Oh, yes!
[...]