How do I tell my boyfriend that it is getting boring in bed whithout hurting his feelings?

I loved but we have been together 6 months and it's always the same thing and getting boring. I want to spice thing up a bit. I don't want to ruin anything but everytime I tell him something needs to be changed he plays all "woe is me. Just break up with me then or you don't like anything I do." What should I do?