tattles
tat-tles
verb
Reveals secrets or spreads gossip about others, often in a childish way.
"He tattles on his sister constantly."
Thesaurus
Synonyms: telling, tattle, singing, gabble, prate, gibber, maunder, clack, tittle-tattle, palaver, blabber, twaddle
Antonyms: keep one's mouth shut, keep quiet, shut one's mouth