It was profoundly strange, to chase after your own naked sister in a public path. Granted, we hadn't seen anyone here since I began running, but still, the probabilities were not zero! As I ran, I caught glimpses of her trough the trees, and sometimes had a great view of her athletic body running in front of me. The cliff at the end of the path was coming really soon, and I wasn't sure I would be able to catch her. But the thought of doing our exercises naked together was enough to send an added shot of adrenaline and testosterone through my system and before we reached the top...