誓言谎言仅一字之差
[shì yán huăng yán jĭn yī zì zhī chā]
The Chinese characters for 'vow' (誓言) and 'lie' (谎言) have only one character different, which is used to indicate the very subtle difference between a commitment and falsehood. This may express some feelings about the thin line between loyalty and deceit or disillusionment with love.