当一个逗比不逗的时候
[dāng yī gè dòu bĭ bù dòu de shí hòu]
'When A Clown Is Not Being Funny' can describe a situation where a usually jovial or clownish person takes a serious moment. It's often used in casual contexts, perhaps to express confusion about a friend who doesn’t act their normal self or simply reflects humorously on the dichotomy of character traits.