Casual vs. in-love

I've never been in love with someone I've had sex with. I have loved someone I had sex with but it wasn't a two way street. I've been with four people, and I would take three of them back if I could. The only one I WOULDN'T take back, is the one I DIDN'T have feelings for, just because of the lack of hurt that was there for the others. What are your thoughts on this (love's significance I guess)?