To break a confidence or a trust. When someone confides something Very personal & private to you; trusting you to Keep it confidential only to discover that they were betrayed & the 'private' conversation you had with them has now been told to several other people.
Confidence Betrayal Trust Private Persoanl
...."I feel SO hurt; I trusted Amber with something very Personal & now I'm hearing several people talking about it. I Can't believe she Spilled On me like that!"......"Tina broke a confidence; she Spilled On me; she just Can't be trusted to keep her mouth shut"