Seducing My Sister Part-1

I am karan a 27 yr old guy from Delhi. This is the story when I was in class 1oth and my sis was in class 12th. We lived in a duplex house. Before coming to the main story let me introduce you to my sis Nidhi. She was slim fair 5.5 slender figure girl who was kinda open minded, lets say semi conservative. We had a very friendly relation between us. Many of my friends had crush on her but she