Can this effect it...?

My boyfriend and I been ttc for a year and half now and i know its him because he never got his ex pregnant of 2 1/2 years, and now she has a kid. but he never drinks water. I try to make him and convince him how important it is. All he drinks is soda after soda. I drink so much water like bottle after bottle of water and walk him to at least drink a bottle a day... Advice? Can this be affecting it?