Tony's little stepsister Melody Marks distracts him from watching TV to ask for tips on improving her cardio. After a little bit of coaxing, Tony agrees to give Melody some tips. He starts by checking out her workout outfit and asking if she has any equipment. Melody comes back with a jump rope and agrees to let Tony record her. They move from one exercise to another, and with each one Melody's shirt falls a little further down her arms to expose her boobs. Melody hates everything about her workout, so Tony finally tells her that raunchy sex is another form of cardio. Melody thinks about it for a bit, but ultimately she agrees. She starts her sexy new cardio on Tony's cock as she pulls it out to start sucking. Tony encourages her all the way, telling his sis just what to do as she strokes and deep throats his hardon. When they relocate to the bedroom, all bets are off as Melody explores a whole new world of exercise that she didn't know existed. She starts out on her hands and knees with Tony peeling off her sports shorts and panties. Then she rolls onto her back and spreads her thighs as she rubs her own nipples, presenting a double whammy of hotness for Tony to enjoy. Tony shoves it in as Melody is on her back and listens to the chorus of her moans. He gets his hands on those busty titties as he fucks his sister. Then he puts Melody on her stomach so he can go to town with a doggy style pussy pounding that leaves Melody panting. Knowing she needs to work it until she's breathless, Melody climbs onto Tony's dick and completes her workout with a stiffie ride! As soon as she has enjoyed both reverse cowgirl and cowgirl, Melody climbs down and swallow's Tony's dick again until he nuts in her mouth. That's the type of workout this horny sister can enjoy!