spoilsport
A spoilsport is a person who, by their behavior, spoils the enjoyment of others. This term is often used informally to describe someone who dampens enthusiasm or ruins a good time, particularly in recreational or social settings. The actions of a spoilsport can range from complaining or being excessively negative to deliberately undermining a game, activity, or event.
The motivation behind a spoilsport's behavior can vary. Sometimes it stems from insecurity, envy, or a desire
Identifying someone as a spoilsport is subjective and depends on the context and the perspectives of those