They were young and very much in love. The future without each other looks blank. They couldn't bear imaging one with the other not being in it and then the idea stroke. Yes! They've heard about the blood covenant, even watched it in the movie and so with so much desire to stay together, he got a razor blade, cut their fingers, touched it together and vowed to never part. If anyone choose to live, it must be a mutual agreement and they licked the blood off each other fingers.
