红杏出墙破草出土
[hóng xìng chū qiáng pò căo chū tŭ]
In traditional Chinese context, 'Red Apricot out of Wall' refers to infidelity. The rest part 'Grass Breaking Ground' usually symbolizes things coming up to the surface or something new starting. Combined together, this may be an expression with dark connotation suggesting some scandalous or inappropriate relationship.