not have the heart (to do something)
idiomPart ofheart
not have the heart (to do something) — idiom
1. To be unable to do something because it would make someone sad or upset.
1.idiom
Definition
To be unable to do something because it would make someone sad or upset.
Example
I didn't have the heart to tell her the bad news.
He couldn't have the heart to fire the loyal employee.