Just let them go!! I have never regretted loving anybody and when the do leave the always always find out the difference and want to come back.But it's my principle,no second chance because if it was rosy on the other side you wouldn't know my worth. Hence I stick that person that loved me blindly. In every relationship ensure you gave your best and be certain he/she can't find another like you that way you wouldn't feel hurt or betrayed. I have never been heart broken because I anticipate very move and I read people well. If you can love not to impress but to be happy then you wouldn't feel so hurt when they leave.