burst my bubble
The act of someone who is downing your up or telling you that what you think is right is wrong
"I'm going to draw a picture with purple paint!" says Jerry. "We don't have any paint." says Mike. "Don't burst my bubble!" says Jerry. In this case Mike is make Jerry unhappy by telling him the opposite of what he wanted to hear.
Burst My Bubble
When somebody pokes your ass with a needle.
He burst my bubble with a needle.