名花有主心有所属
[míng huā yŏu zhŭ xīn yŏu suŏ shŭ]
Translating as 'the named flower already has an owner and the heart already belongs to someone', it generally refers to someone (usually a woman) being engaged or taken by someone else, and has feelings for someone specific in their heart. It’s commonly used in romantic settings and implies loyalty in love.