According to Wiktionary, spill the tea (idiomatic, informal) means:
To disclose information, especially of a sensitive nature.
Apparently, the expression appears to be a recent one.
2012, Demetria L. Lucas, "Should I Worry That He Earns Less Money?", CARE, Issue #18, October 2012, page 18:
- They are up in your business because you invited them in by spilling the tea on what you and your man earn.
And recently on YouTube, I read this comment
Can anyone tell me where it comes from? Is it British or American in origin?