put a damper on
US /pʊt ə ˈdæmpər ɑn/
UK /pʊt ə ˈdæmpər ɑn/
1.
to have a negative effect on something, making it less enjoyable or successful
:
•
The bad weather really put a damper on our picnic plans.
•
His negative attitude always puts a damper on team morale.