眼泪只是卖笑之后的赠品
[yăn lèi zhĭ shì mài xiào zhī hòu de zèng pĭn]
'Tears are just a bonus after laughing/selling smiles.' It suggests that someone might laugh or pretend to be happy on the surface even though they are sad inside; tears come as unexpected results of faking happiness. There's underlying sadness masked by laughter.