I do not think that you should tell your parents. For one, please do not place yourself in a dangerous situation. For another, you should tell about something so deeply personal only if you trust the people you are confiding in. Based on your posts, your parents have done absolutely nothing to deserve your trust.

I agree with Hamster on this. I would be careful about placing yourself in a dangerous situation. Confrontation seldom works when people have convinced themselves they know all the answers. Also one can only confront someone from a position of strength which you do not have with your father. I would think carefully about sharing things though with people, regardless or who they are, if you are not in a place of trust and it is not a safe place to do so.