throw a wet blanket over (something)
To make something be or seem less enjoyable, successful, or important. The court's decision throws a wet blanket over the president's plans for healthcare reform. Her crappy attitude really threw a wet blanket over the party. I could tell that Sean's football victory threw a wet blanket over Sam's news about getting into the college she wanted.
throw a wet blanket over something
AMERICANIf something throws a wet blanket over an event or situation, it makes it less successful or enjoyable. Cool, rainy weather has thrown a wet blanket over Michigan's tourism season.