Jason is doing a science project that is making his stepmom, Emily Addison, very uncomfortable. He's trying to measure whether the size of a lady's boobs is correlated with her level of estrogen. Once Emily has checked with Jason's dad to make sure this is kosher, she reluctantly answers his questions. When her patience runs thin, Emily decides to whip out her titties and have Jason just go to town comparing them if it'll make the process go faster. Jason does as he's asked, but Emily can tell her stepson is getting a hardon that is, frankly, impressive.
Emily offers to help Jason take care of his problem. After a bit of back and forth, Jason relents and lets his horny stepmommy wrap her hand around his cock. Drawing him to her mouth, she opens wide to start sucking him off right there in the living room. Getting a deep throat BJ from his stepmom wasn't what Jason expected, but it's everything he wants. He can't stop groaning as Emily shows him that milfs give the very best BJs.
Climbing onto the couch, Emily spreads her thighs so Jason can sink balls deep into her hairy pussy. Her big titties are in constant motion as Jason bangs her hard. Leaning over the couch arm, Emily presses her face into the couch so Jason can fuck her from behind. She even spreads her ass cheeks to give her a view of her chocolate starfish as he pounds her. They relocate to the bedroom where Jason lays down and lets Emily go to town on him in cowgirl and reverse cowgirl. When Emily gets on her back and lets Jason give her one last big O, they both know he's earned his own orgasm. He pulls out and covers his stepmom's muff with his cum shot, after which they both agree Jason's dad can never know.