Antonyms for the phrase "keeps lid on" would mean the opposite of controlling or containing a situation. Instead of keeping something restrained, the antonyms would suggest releasing, disclosing, or exposing information or emotions. Some opposite phrases could include "reveals all," "spills the beans," "opens up," or "unleashes." The antonyms of "keeps lid on" would indicate that there are no more secrets, and everyone will know what is going on, leaving nothing hidden or subdued. Essentially, "keeps lid on" means to keep something under wraps or hidden, while its antonyms would suggest exposing it to the light or setting it free.