Leo Valentino is hanging out in his room when his stepsister Scarlet Skies barges in. She's looking for Leo's science project so she can copy it. When Leo kicks her out, Scarlet claims she's going to make her project about how much Leo masturbates all the time. She devises a plan to get some pleasure and her project. The next day, Scarlet contrives it so Leo thinks he's alone. He goes to his room to masturbate, only to find her in a sexy lab coat and nothing else. Claiming it's for her project, Scarlet insists that Leo jerk off and answer her questions. When Scarlet inquires whether Leo wants the real thing, she obliges him with a deal. If Leo can eat her out and make her cum, Scarlet will give him the real deal. Leo makes Scarlet moan just as she'd hoped. She turns around to suck Leo's dick and then climbs on top to ride her stepbro in cowgirl. Getting on her knees, Scarlet begs for the D more and more. She's on her back as Leo fucks her. When he's on the verge of cumming, Scarlet wraps her legs around him to keep him buried in her twat so he creampies her, which was the real experiment all along.
