Hahaha...I don't know. Perhaps I will try to find out if there is such an idiom; I believe the traditional Chinese sense of honor is no less strong (though it'd have to be /somewhat/ less foolish) than the Spanish.

>not saying this to someone arrogant enough to speak English would have been culturally inappropriate
Your negatives confuse me. What? (I'm going to assume the first "not" shouldn't be there.)