"Telling all" is an expression used to describe someone revealing every detail or secret they know. If you're looking for synonyms to replace this phrase, you might consider using "spilling the beans," "letting the cat out of the bag," or "divulging everything." Other options could include "revealing all," "sharing every detail," or "disclosing everything." Whether you're discussing a gossipy friend, a confidential confession, or any other situation where someone is sharing a lot of information, there are plenty of phrases you can use to convey this idea without repeating the same phrase over and over again.