A boy uses "yogurt" to describe a girl. What does this mean? What does yogurt mean here?

That is to say, this girl is jealous, which means sour. It also represents this girl's mother-in-law, like an old woman.

Jealousy is a synonym and metaphor for jealousy. It is said that this allusion comes from the court of the Tang Dynasty. In order to win the hearts of the people, Emperor Taizong wanted to marry a concubine for the prime minister. The minister's wife intervened out of jealousy, but refused to let him do so. Emperor Taizong had no choice but to let the minister's wife choose between drinking poisoned wine and concubinage.

I didn't expect Mrs. Fang to be a little strong-willed and would rather die than bow before the emperor. So I picked up the "poisoned wine" and gulped it down. Mrs. Fang finished drinking with tears, only to find that the cup was not poisonous wine, but thick vinegar with sweet and sour taste. Since then, "jealousy" and "jealousy" have become one, and "jealousy" has become a metaphor of jealousy.