How do I tell a regular he reeks like piss?

I have a pair of older gentleman who come for coffee every Friday night, they’re perfectly polite but the one reeks like piss to the point that it makes the entire section nauseating. This week he said ‘it always smells like piss when I come here’ and I was speechless. It is very obviously from him, when you get near him it makes your eyes water. How do I bring this up? I feel bad for the people sitting near him.