Some seek solace temporary and when they get bored they leave abruptly. Some expect honestly from you and keep throwing lies on your face. Some talk about rules and regulation but they themselves follow not. Some fool you. Some make fun of you.  Some have a give and take relationship and always expect a lot.
Some get hurt by even a forward and dont communicate for ages.
Some just want appreciation but will never give when the time come.
And some simply block you or unfriend you.

Respect their decision from my heart but if the same had to be done, why come close and near.  
Why not  be honest in expressing their opinion after the relationship goes more stronger and just leave and move on.