Some things are better left unknown, especially when dealing with people who think changing their underwear more than once a week is a waste of precious soap and water.
I worked with a European fellow who had that 'little problem.'
No body wanted to get close to him because he stank. We thought he was not playing fireman at his bathroom stall on a daily basis, like it is customary in America.
Then someone finally talked to him and discovered the reason for his smell... he kept using repeatedly the same undershirt and underpants, even though he showered every day.
After he changed his underwear habits, his peculiar smell went away.