Your 18 year old sister Tina

You see your sister Tina going into her room. You and your sister were quite good friends. You slip under her door into her room and see her sitting on her desk doing homework. She has a beautiful face and long brown hair. She had a nice little ass, that was still in good shape, and B-cup boobs. She was wearing a black skirt and a T-shirt.

You go over to her and climb up her chair. You go under her black skirt and go into her black panties. She doesn't feel as you enter her pussy. For a moment you black out before you open your eyes again and feel yourself sitting on the chair. You look down to see your sister's desk with a maths book laying on it. But more important you were wearing a red T-shirt with two little boobs on your chest. You felt the weight on your chest and the missing feeling between your legs. You notice how brown hair falls into your view. You possessed your sister!