Stepbro jerks off to masturbating stepsister in front of her

You are feeling horny and since nobody is home you decide to jerk off right in the living room. Suddenly your stepsister walks in and catches you right in the act. Instead of running away, she is curious to see you and wants to stay and watch you. Will you let her watch you jerk off? Little by little things take a turn to more taboo and next thing you know, you are licking her pussy until she screams for mercy until you two almost get caught by the parents.