not all roses idiom (also not a bed of roses)
不尽如人意;并非尽善尽美
If a situation is not all roses, there are unpleasant things to deal with as well as the pleasant ones.
Being in a relationship is not all roses, you know. 你知道，谈恋爱并非总是柔情蜜意，也有不如意的事。