TF gave you a great explanation, one more thing to add is that initially in replay when all their antics are going on, the reason for this is that they are searching for a way to relieve their pain. They blame you or anyone else in their way, they want to get rid of you and replace you with another person in order to search for a reason to eliminate their pain. They will go down every dead end street try to prove that they can get rid of their hurt. That is why most om/ow/op relationships do not work.
