|If your manager persists with his so-called fun, perhaps he should think about buying a vowel for this word: L_WSUIT. Regardless of his intent, his hurtful comments smack of discrimination based on national origin, and that's just asking to get smacked with litigation.|
It is rather amazing that there are still people around who make comments like this. Those who do so must either live under a huge rock, or they are unbelievably insensitive, uniformed, self-absorbed, or misguided, or a combination of all of these delightful characteristics.
You should deal directly and firmly with this individual. Tell him that you find his comments to be cruel and hurtful, and then add that they have to stop immediately. End the discussion by telling him that you hope you do not have to take any further action on this matter, but you will if you must. If he still does not get the message, then you should deliver it to his manager.