In a secret underground lab, a horny, busty BBW scientist gets more than she bargained for when she activates an alien probe. It transforms before her, growing into a towering, muscular form, its enormous black cock standing at attention. She can't resist, her small tits aching as she approaches, her big ass swaying. She kneels, taking the alien's cock into her mouth, gagging as it hits the back of her throat. He growls, his hands reaching down to grab her big ass, lifting her onto his cock, impaling her on his length as he begins to fuck her, his hips moving with a force that makes her tits bounce.