Relationship Taboo?

I've been liking this guy for awhile. We dated but have not been in a committed relationship. When we got together he was in a relationship. He and his girlfriend broke up and we started dating. We were just enjoying each other. I guess I umed what would be would be. I had real feelings for him and thought we were leading up to being a couple. Well we've had several ups and downs along the way but he always comes back to me and I to him. The problem is that he never pushes us p the dating stage. Our last riff was a month ago. We've recently reconciled but now I hear he has a new girlfriend. He's back in my life again but I can't help but wonder what the hell. He's the same old guy flirty and complimentary and attentive as if nothing has changed. My feelings are hurt now. Why was making a commitment to me taboo? I want to say something and I guess at this point it doesn't matter what. I feel I have that right to know. but what to say?