Relaxing together in the bedroom my step sister playing on her phone I start getting horny as she's in a short skirt, her ass so close to being shown. I couldn't resist getting my cock out and starting to stroke it while she was distracted, then testing the waters and starting to lift her skirt up to show her ass. She has such a fantastic plump ass which I couldn't resist touching. Next time I'll have to try and see what lays under those panties