In this interesting article, Dzogchen Ponlop Rinpoche talks about how to deal with abusive relationships. He mentions:
Once I was translating for His Holiness the 17th Karmapa in India, and His Holiness said that if you tolerate such abusive action from anyone, that’s not compassion, and that’s not patience. He gave the example that some people say if someone hits you on the left cheek, you should show them the right cheek. He said that’s not really compassionate action, or a practice of patience. That’s actually very self-centered, ego-centered because you are only caring about yourself. You’re trying to practice tolerance, patience, love, kindness, or whatever you think. But you don’t care about that person’s karma. You don’t care about that person’s path, or helping to transform that person’s negative habits. You’re kind of encouraging that person to engage in more aggression. So in the end, that person’s path is going further and further downward, while yours may be going up and up––because you’re being more tolerant, more patient, and what-have-you. So His Holiness said that’s really ego-centered.