It is tangy, like a citric taste kind of thing, but it's not strong at all, at least on my girlfriend it's not, I love going down on her, no smell, barely any taste, and the little there is it's actually nice, she is extremely clean. I could go down on her all night long, I just love being between her legs, but I need to perfect my technique. My advice would be to keep doing it, take a shower together before doing it, or tell her to wash herself well down there, her diet also has to do with it, if the problem persists just hold your breath and breath through your mouth
