Nipple Problems

So can anyone help me out with this situation. My boyfriend loves to bite and play with my nipples but the other day he told me that they have a foul taste (kind of like onions I guess?) It now makes me extremely insecure and I was wondering does anyone else have this problem? And if so, how do you get rid of it? I'm not sure why this is happening, I am a very clean person and shower daily. Thank you ladies!