Most Helpful Girl
It is both. But since I have come out of an (emotionally) abusive relationship, I know that something like this can come slowly. The abuse creeps is, in such small doses that it can be overlooked. During that time, in my opinion, the fault is with the abuser.
BUT as soon as the "weaker" party is aware of it, the person must get out of the relationship. If he/she doesn't, then it is their own fault.
This could mean any relationship. It doesn't have to be a romantic one.