Don't trust that fucker; he's always up to no good.

别信那个混蛋，他总是没安好心。

Her smile makes me feel she is up to no good.

她的笑容让我觉得她不怀好意。

He is always sneaky; he must be up to no good.

他总是躲躲闪闪，肯定不怀好意。

Every time I see that scally, he's up to no good.

每次我看到那个淘气鬼，他都在搞恶作剧。

You'd better stay away from those who are up to no good.

你最好离那些不怀好意的人远一点。

They are whispering in the corner, looking up to no good.

他们在角落里偷偷说话，看起来不怀好意。

I think that person is up to no good; we should be careful.

我觉得那个人不怀好意，我们最好小心点。

The snake is up to no good.

这条蛇真是居心叵测啊。

I knew he was up to no good.

我知道他图谋不轨.

I think Ken's up to no good.

我想肯正在干坏事。