Qiānwàn bié jià gěi nà zhǒng huāhuāgōngzǐ, tā bù huì zhēnxīn dài nǐ.
Whatever you do, don't marry that sort of playboy — he won't treat you sincerely.
Tips
history
Found in the Qing-dynasty satirical novel 《何典》: 活死人便知他是个仗官托势的花花公子了 — 'Living-Dead-Man saw at once that he was a flashy playboy relying on official connections.'
culture
Also the Chinese name for the Playboy magazine brand (花花公子). 花花 evokes flashiness and indulgence; 公子 originally meant 'son of nobility' — together, the spoiled rich kid stereotype.