The thoughts and hopes of being together one day was just the committed guy's dream and not of the other. And it was a bit confusing for the committed guy to find out about it. He thought, they saw something special between them that’s why the guy is holding on - apparently not. Could the guy have realized how unworthy for a commitment the committed guy is? Or is he really just not ready for it yet? What is the benefit he gets from it anyway? Why hold on if you cant see him as your partner one day? An unexplained benefit he gets or something he could but chose not to identify to himself?