Sex && Pregnancy..

So I am 5 months pregnant today && Even though I have been told that my sex drive is going to go through the roof, it has been the complete opposite. My fiancé is IN LOVE with the whole pregnant look on me && Says that it makes him horny just looking at me, so he always wants to have sex. I have absolutely no desire to have sex at all. ALL things sexual are displeasing to me in all ways. I have only been this way since I have been pregnant. Anyways, since I don't want to have sex at all && He wants it all of the time, I don't know what to do.