Yeah, it was one sided. That's what makes it so tragic, he falls in love with a woman who falls for Hojo (definitely not in the looks department, thats for sure). But being the selfless thing that he is, he is just happy that they are happy.

But there are the rumours that (SPOILER)Vincent could be Sephiroth's father, and not Hojo's. The boy had to get his looks from somewhere.