one's ulterior motive; one's real intention lies elsewhere; one's hidden agenda
他提议周末去公园野餐，其实醉翁之意在于想让我们帮他完成一个项目。
He suggested a picnic in the park this weekend, but his real intention is to get us to help him finish a project.
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one's ulterior motive; one's real intention lies elsewhere; one's hidden agenda