是某人自己的責任,是某人自己的事
be sb's lookout
(認為某人的行為不明智)是某人自己的責任,是某人自己的事
used to say that you do not think sb's actions are sensible, but that it is their own problem or responsibility
If he wants to waste his money, that's his lookout.他要亂花錢,那是他自己的事。
釋義來自《牛津高階英漢雙解詞典》第 9 版