To avoid creating any controversy, and thus avoid being a target for anybody's criticism.

Alternative form of keep a civil tongue in one's head

(idiomatic) To maintain a polite manner of speaking.

(rhetorical question, colloquial) One should not do something that one has hired someone else to do.

(humorous) A supposed motto describing the dynamics of incest.

Third-person singular simple present indicative form of keep one's head above water

Alternative form of an apple a day keeps the doctor away

(idiomatic) To avoid revealing one's thoughts, circumstances, or plans.

Alternative form of keep one's head

A woman will be more interested in a man if he is not kind to her.