老婆的闺蜜我不惹老公的兄弟我不沾
[lăo pó de guī mì wŏ bù rĕ lăo gōng de xiōng dì wŏ bù zhān]
Literally 'I do not provoke my wife's close female friend and keep a respectful distance with my husband's male friends,' which conveys an attitude to maintain harmonious family relations and boundaries in complicated marital situations.