spoil·sport 
/ˈspojəlˌspoɚt/ noun
plural spoil·sports /ˈspojəlˌspoɚt/ noun [count] informal : someone who spoils other people's fun or enjoyment
▪ Oh, don't be a spoilsport. Let them try it. ▪ Dad's a spoilsport. He won't let us play football.
▪ Oh, don't be a spoilsport. Let them try it. ▪ Dad's a spoilsport. He won't let us play football.
