Digging your own grave...

Feelings are rarely, if ever, equally matched. Most always, one person is more invested than the other.
That person is the one who ends up getting hurt. They are the one who eventually gets left behind. Some know they care more; some, however, do not. It ends up worse when one has to find out later on in the relationship. Then, there is that painful aspect of constantly being lied to. Thus, the person who cared more ends up feeling betrayed, broken, and alone.