To kiss and tell is defined as to share your romantic exploits, especially those of a sexual nature, with others.
An example of kiss and tell is when a guy kisses the prom queen and then shares the news with the whole school.
Informal revealing personal or confidential information, as about a well-known person, gained from the author's close relationship with that person: a kiss-and-tell memoir
Disclosing private or confidential information, especially in a firsthand account: a kiss-and-tell memoir by a presidential aide.
- kiss and tell