happy camper
US /ˈhæp.i ˈkæm.pər/
UK /ˈhæp.i ˈkæm.pər/

1.
a person who is happy and satisfied with a situation
:
•
After getting a raise, he's a really happy camper.
•
If you give her what she wants, she'll be a happy camper.
2.
a person who is not happy or satisfied with a situation (often used in negative constructions)
:
•
He's definitely not a happy camper after losing his job.
•
The customers were not happy campers when the flight was delayed for hours.