sticking out one's tongue when putting food in one's mouth
Colloquial term describing the habit of extending the tongue to meet incoming food, often considered poor table manners.
The parent scolded the child for sticking out their tongue when eating.
Sticking out your tongue when eating is often considered bad manners.
Compound of 迎え (mukae, 'meeting, greeting') and 舌 (shita, 'tongue'), literally 'greeting tongue'. The exact origin is uncertain, but it vividly describes the tongue moving forward to meet food.