Dear Readers: How can I tell my boss that he has mouth odour

From a reader

I just got a job with an auditing firm with a fantastic pay. I love everything about my job except that my direct boss wants to chase me out of the office with his bad breathe. Its so bad. I can't even describe it. I have tried to cope within this two months I started but mehn....Kai.... its getting to me now. How can I respectfully tell him without getting myself thrown out of my job? I need your sensible advice please.