that's/it's somebody's lookoutBritish EnglishBrE informal used to say that someone is responsible for deciding what they will do, and will have to suffer any bad results 那是某人自己的事;这是某人自己的责任 If he wants to keep seeing her, that's his lookout. 要是他想继续跟她在一起,那是他自己的事。
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