The idiom "rain on someone's parade" means to spoil or ruin someone's plans or happiness, often by saying or doing something negative or discouraging.
For example, if someone is excitedly telling you about their plans for a party, and you respond by saying "Well, I heard it's going to rain that day," you are "raining on their parade." You are taking away their excitement and enthusiasm by introducing a negative aspect to their plans.
This idiom is often used when someone is being overly negative or critical about something that others are excited about. It can also be used to describe someone who is intentionally trying to ruin someone else's plans or happiness.
In short, "rain on someone's parade" means to spoil someone's enjoyment or excitement by being negative or critical.
• The politician's scandal rained on the parade of their campaign, causing them to lose the election.
• I hate to rain on your parade, but I don't think your plan is going to work.
• He was excited to go to the beach, but the rain on his parade and he had to stay home.
• The team was celebrating their victory, but the coach rained on their parade by pointing out all the mistakes they made.
• The company's profits were up, but the CEO's negative comments rained on everyone's parade.
• My friend was so excited to show off her new dress, but the rain on her parade when she spilled coffee on it.