Р183
POT ДО УШЕЙ (у кого)
collNPfixed WO 1. a large mouth
whale (cavern) of a mouth.
2. s.o. is laughing or smiling in such a manner that his mouth seems to stretch all the way to his ears: (y X-a) - ' X is grinning from ear to ear. Cf. X is grinning like a Cheshire cat.