have a fit不是“试穿” ，而是“勃然大怒；大发雷霆；大光其火；大吃一惊”。

【例句】
My old mother would have a fit if she knew.
我妈妈要是知道了这事情肯定会大吃一惊。

He'd have a fit if he knew what we were up to!
要是他知道我们在干什么会气疯了的。