“蚌埠,” referring to a city in East China’s Anhui Province, is a homophone of “绷不” (bēngbú), used here for a humorous effect. The term “绷不住了,” literally meaning “cannot keep it tight,” is coined by Chinese netizens to use in situations where one cannot hold one’s laughter, tears, fury or other responses, deciding on the context. It’s roughly translated as “cannot hold it.”
Wǒ fā gěi nǐ de shìpín kànleméi？
Did you watch the video I sent?
Kàn le，shìpín lǐ de xiǎogē tài kělè le，tā yī kāikǒu wǒ jiù bèngbùzhùle。
I did. The guy in the video is so funny. I couldn’t hold my laughter the moment he opened his mouth to talk.