(in the) palm of someone's hand; (under) someone's complete control; (at) someone's mercy
to flip-flop; to do an about-face; (lit.) to flip over one's hand; to do something easy
to flip-flop; to do an about-face; (lit.) to flip over one's hand; to do something easy
sudden reversal (of behavior, opinion, attitude, etc.); about-face; flip-flop