花心男子也有痴情时绝情女子也有心软时
[huā xīn nán zi yĕ yŏu chī qíng shí jué qíng nǚ zi yĕ yŏu xīn ruăn shí]
'Even womanizers have periods of deep love; even heartless women have times when they are soft-hearted.' It speaks of dualities in personality traits and unexpected sides of people's characters.