show off in the presence of an expert; teach fish to swim; teach one's grandmother (how) to suck eggs
Related Translations:
夫子: 1.(学者、老师之旧称) an ancient form of address to a confucian scholar in a respective way or to a master by his disciples2.(迂腐之人) pedant 短语和例子迂夫子 a pedantic old fogey3.(旧时妻称夫) husband