I had this problem about a year ago, my boyfriend HATED prog metal especially Symphony X and teased me about them all the time. At first I thought I could handle it, but then I realised that my music is a part of my soul, so disrespecting that is disrespecting me. Not everyone has to like your music sure.. but someone who supposedly loves you is supposed to respect it and would help if they find at least some quality in it to be able to handle it.
Anyway I dumped him.. not because of that (it was only the start of seeing it wouldnt work out), but my metal is too important for me for my partner not to at least like a little. And anything that is a little crack in the surface when your dating, quickly becomes a ravine when youre married. So you might want to try and work out that part of the relationship and come to an agreement you're happy with before it eats away at you. Certainly not to say that things cant work out if you dont like each others music, but the respect of each others tastes is so important i cannot stress enough.