I was talking with a middle-aged Chinese friend recently who admitted to finding a young Korean pop star very handsome. “Really? Wow,” I said. “You’re really robbing the cradle.” She didn’t know that idiom, so I explained it to her.
She laughed and then she reciprocated, telling me that in Chinese, the same idea is expressed as lao niu chi nen cao (老牛吃嫩草), which literally means “old cow eating tender grass.”
I love it. Like may Chinese idioms, it’s earthy and hilarious.
Apparently Thai has a similar expression, according to one of my commenters.