A person who takes the fun out of a situation or activity, as by pessimism, demands, dullness, etc
disapproval If you say that someone is a wet blanket, you are criticizing them because they refuse to join other people in an enjoyable activity or because they want to stop other people enjoying themselves. = spoilsport. One that discourages enjoyment or enthusiasm. someone who seems to want to spoil other people's fun, for example by refusing to join them in something enjoyable that they are doing