My Step-SISTER lets me dry hump her to get back at her Boyfriend

Description: I've always been obsessed with my step-sisters legs.. i comes into her room to talk to her and can't help but ask if i can sit on her lap.. she tells me no, and then i fill her in that her boyfriend is currently on a date with some slut.. she decides to get revenge, and let me dry hump her as long and as hard as i want until i cum all over her.. while she tells her boyfriend all about it on the phone.