I thought she was acting foolishly, but I 'bit my tongue' [='held my tongue'] and didn't say anything.
The news of their engagement 'set tongues wagging'. = 'Tongues were wagging' over their engagement.
He speaks English fluently but his 'mother tongue' [='native language, first language'] is Chinese.
(..) "They would die before talking". Where does he find these guys? Open the champagne. - And can we get some girls in here? - Careful what you wish for. - Cat got your tongue? - You dumb bitch. Nobody ever accused me of being dumb. You're dumb... for comin' here tonight. (..)2012 The Dark Knight Rises