a shut mouth catches no flies

a shut mouth catches no flies

It is better to keep one's mouth shut (not say anything) than to engage in idle chatter (and potentially say something inappropriate). I would suggest that we all just sit quietly until tea time commences—a shut mouth catches no flies, after all. Keeping in mind that a shut mouth catches no flies, I made sure not to say anything out of turn during the meeting.
See also: catch, flies, mouth, shut