to disappear like a stone dropped into the sea / to vanish forever without trace
万古长新
wàn gǔ cháng xīn
to remain forever new (idiom)
青春永驻
qīng chūn yǒng zhù
to stay young forever
躲得过初一,躲不过十五
duǒ de guò chū yī , duǒ bù guò shí wǔ
lit. you may go undetected during the new moon, but at full moon you'll be found out (idiom) / fig. you can't put it off forever / sooner or later you'll have to deal with it
丑媳妇早晚也得见公婆
chǒu xí fù zǎo wǎn yě děi jiàn gōng pó
lit. the ugly daughter-in-law must sooner or later meet her parents-in-law (idiom) / fig. it's not something you can avoid forever