His back is up because you criticized his work.
one's back is up
idiomOne is offended or angry.
Origin
disputed originFrom the way a cat, when angry, raises or arches its back.
I tried to offer some helpful advice, but her back was up immediately and she refused to listen.
The politician's back was up after the journalist questioned his integrity, leading to a heated and defensive response during the live interview.
- 01
abound in one's own sense
To follow one’s own inclinations and opinions.
- 02
ace up one's sleeve
A surprise advantage of which others are not aware.
- 03
act one's age
To behave in a manner appropriate to one's age.
- 04
act one's age, not one's shoe size
Synonym of act one's age (“to behave in a mature manner; to avoid being childish”).
- 05
afraid of one's own shadow
Exceptionally timid.
- 06
air one's dirty laundry in public
To reveal one's sordid secrets to the public.
- 07
air one's dirty linen in public
Synonym of air one's dirty laundry in public.
- 08
albatross around one's neck
A characteristic, possession, associate, or previous deed that hinders one's ability to succeed.
Last updated July 12, 2026