skate on thin ice字面意思在薄冰上滑冰，引申为如履薄冰；身历险境。

【例句】
If you are not in a small group, you are skating on thin ice and you don’t know when you might fall through.
如果你没有在一个小集体里，那么，你的生活将会如履薄冰，你不知道何时会落入水中。

But your were playing video games all afternoon. You are skating on thin ice.
但是你一个下午都在玩游戏，你现在的情况很危急呀。