此女有夫请勿调戏此男有妻请勿勾引
[cĭ nǚ yŏu fū qĭng wù diào xì cĭ nán yŏu qī qĭng wù gōu yĭn]
"This Woman Is Married Please Don't Tease; This Man Has a Wife Please Do Not Seduce" clearly marks the boundaries, politely but firmly discouraging inappropriate advances on married individuals.