Going Away Present

Natalia is your step-sister who you've always had a crush on, your parents are out of the house and Natalia comes into the lounge to watch a film but she spots you and realizes that isn't going to happen. She is wearing a very short white skirt and red knickers and you are starting to get a hard dick, you decide to come up with a plan that will get Natalia excited enough to let you wank over her.