"laugh in your sleeve" in Chinese (Simplified)
暗自发笑偷偷地笑
Definition
偷偷觉得某事好笑，尤其是取笑别人时，表面上不表现出来。
Usage Notes (Chinese (Simplified))
偏书面语或文学性，表达悄悄嘲笑他人。与‘大笑’不同，强调隐藏情绪。
Examples
Sometimes, people laugh in their sleeve when someone makes a mistake.
有时，当有人犯错时，人们会**暗自发笑**。
He didn't show it, but he was laughing in his sleeve at her idea.
他没有表现出来，但他**在袖子里偷偷地笑**她的想法。
When the teacher slipped, the students laughed in their sleeve so she wouldn't notice.
老师滑倒时，学生们**偷偷地笑了笑**，不让她发现。
You could see John laughing in his sleeve during the awkward meeting.
你能看出约翰在那场尴尬会议上**暗自发笑**。
While everyone praised the boss, Maria was laughing in her sleeve at his terrible joke.
大家都在夸老板时，玛丽亚**暗自发笑**他的烂笑话。
He always tries to be nice, but sometimes you just know he's laughing in his sleeve.
他总是装得很友好，但有时你一看就知道他**在暗自发笑**。