xǐ bù zì jìn

not being able to contain oneself with joy

The Chinese phrase '喜不自禁' describes a state of overwhelming joy or happiness where a person cannot help but express their emotions. It is often used in contexts where someone feels such excitement or happiness that they have to show it, whether through laughter, speech, or other expressions. This phrase can be used in both formal and informal settings to convey a deep sense of delight.