你敢抢我男人我就当你妈
[nĭ găn qiăng wŏ nán rén wŏ jiù dāng nĭ mā]
Translated loosely as 'If you dare snatch my man, then count on me being your mother.', it's often used humorously or confrontationally suggesting strong protection towards their partner and warning against interference, but should be treated cautiously as the original carries a confrontational nuance.