小事一桩啦

你想和他保持良好关系的话，去敲他办公室的门，然后关起门，一对一说“I know you use it as a friendly nickname, but I really don't appreciate being called 'Sneaky'. It makes me uncomfortable, and quite frankly, I find it offensive. It would be great if you could call me (John) , like everyone else does. Would that be OK with you? ” 然后借机下坡，夸他两句，说说以后继续合作愉快，男人对男人的握个手，等等，阐明了立场，也别让他太尴尬。

我觉得你脸皮薄的话，写email也行。