In this life, in a time or two, I have encountered few people that have saved me. They don't notice how they action have helped me a lot, but I do. I believe most of us have those kind of people in their life. Those whom we will always be grateful to. Those whose even death would make us pay tribute to. Towards those people, we would always try everything possible to pay back what they did for us. They might have stayed with us in our darkness days or they might just had faith in us when nobody did. In short, what they did were remarkable for our existence.
Towards those people, we just cannot get mad because we know that we won't survive without them. Towards those people, anger is taboo since we won't have any single gut to do so. Towards those people, no matter how much you want to stay away and hate them for all the wrongdoings they did, you just cannot. Why? because one kindness they gave you back then, was so precious and happened in the right time - that you will be able to forgive all the crimes they did to you. Because all of their sins towards you were incomparable with the one thing they did that saved you.
Now, how if that particular one you saved was also the one who saved you? In all sense, all you have in between is just a mutual gratitude - not more, ain't I right?