What's (someone's) game?
informal
something that you say when you want to know the real reason for someone's behaviour.
You're being exceptionally nice today. What's your game?
英语词组固定搭配大全包含18674条英汉双解词组，基本涵盖了全部常用英文词组、短语的翻译及用法，是英语学习的有利工具。