One Sided Love:
This type of love does not seem to be mutual, and most people in a "loving couple" tend to discriminate against this, saying it is not a type of love at all. One-sided love commonly occurs when a relationship or marriage breaks, and one person moves on, while their spouse constantly thinks of them and attempts to win them back, often in vain.
It also happens when someone has fallen for their best friend, or for someone they are involved in a No Strings Attached sexual relationship with.
I think most of us have been there at one point or another in our lives.
Can anything ever come of these?
