有事鍾無豔，無事夏迎春

Etymology
, also known as Zhong Wuyan, was the queen consort of who was talented and famous for her ugliness. She once saved the country by offering the king advice that encouraged him to start reforms.

was a fictional character in folk tales who was said to be a concubine of King Xuan and was very beautiful but with little talent. It was said that when King Xuan has troubles, he would seek for Zhongli Chun. On the contrary, when he was free, he would play with Xia Yingchun instead.

Idiom

 * 1) Someone only reaches his/her friend when the friend is advantageous.