My father got married after our mother died when we were teenagers, he's always travelling and it was our step-mother who take care of us. Me and my sister always saw her like an older sister, never like a mother. When we were around our 20s she hang out with us and our friends, she was the wildest of the group. She started to like my sister in a different way around this time and soon they invited me to join them. Now it's wild parties every time at home and our father is getting suspicous.