Milf step-mom in sexy lingerie and nerd man having sex

The next night I got home late after a night out with some friends. When I got home, the house was quiet - everyone was quiet.. I went to check up on my step-mom before bed, but the master bedroom door was closed. In fact, Zack's sweat sock hung from the handle. I opened the door slightly and could see my step-mom fast in bed..cuddled up in the frat leader's arms, whose eyes were closed. Considering how hot it was outside, it wasn't unusual to see him relaxing shirtless, but my step-mother looked like she wasn't wearing a top either. My step-mother relaxing with a smile on her face. Whatever she and Zack were up to before relaxing, it sure gave her pleasure. Suddenly, Zack's eyes opened, his eyes locked right on mine. I jumped, worried he was going to scold me for waking him up, but he just smiled and reached under the bed sheet, like he was fishing for something near his crotch. He pulled out something with one hand and tossed it to me....