Р182
РАССТЕГНУТЬ POT (ГЛОТКУ)
substand , rude
VPsubj:
human 1. to begin to talk, chatter, sing, swear etc: X рот расстегнул — X opened his mouth (trap, big mouth, big fat mouth, big yap etc).
2. - кому to force s.o. to start talking, singing etc: X Y-y рот расстегнет — X will make Y open his mouth
(in limited contexts) X will force (squeeze) it out of Y.