If you are with someone that you can't say "Hey lady, when I help you get off you hurt me and I don't enjoy it. Its something you make me put up with, do this instead..." you should accept what is happening to you. Could be her indirect way of trying to tell you what to do, but without clear communication it turns sex into a frustration guessing game. I learned the hard way to just say everything about everything and hope for the best in all situations, not just in sex and relationships.
Clawing, scratching, hair pulling, choking and biting = good things. I've only met one male capable of dishing it out right.