笑容背后虚伪幸福背后泡沫
[xiào róng bèi hòu xū wĕi xìng fú bèi hòu pào mò]
The phrase suggests that the smiles and happiness one displays may not be genuine, but a cover-up for underlying deceit or pain. It hints at an unstable happiness, much like a bubble which looks beautiful but will pop eventually.