Looking for flowers and asking for willows comes from Du Fu's "Yan Zhongcheng's White Driving": "The team goes out of the suburbs and asks the willows to find flowers to the wild pavilion." It means enjoying the scenery in spring. Later, I wrote Jin Ping Mei in 1982: Han Daoguo and Lai Bao, and they didn't deliver the goods. They spent the whole day looking for flowers and prostitutes, drinking and prostitution. Metaphor is a prostitute.
It is also often used in contemporary works, such as Kang's Fu Yi Si Gentleman: if you want to have sex, you can do it secretly, and even let the police comrades invite you to the detention center for ideological education aboveboard. You deserve it. If you want to have an affair, do it secretly, and even let her parents catch you red-handed. The evidence is conclusive. You can't stand and talk like it's easy.