hóng xìng chū qiáng
lit. the red apricot tree leans over the garden wall
a wife having an illicit lover (idiom)
xiōng dì xì yú qiáng , wài yù qí wǔ
internal disunity dissolves at the threat of an invasion from outside (idiom)
qiáng
variant of 牆|墙[qiang2], wall