Liz is a 19-year-old teen who’s just getting to explore her body. However, her stepmom and stepbro, Johnny, would like her to focus more on math. While her brother was helping her solve some math problems, she straight-up asked him for relationship advice concerning “butt stuff.” The guy was stunned but didn’t back away. After all, he does want to help her little sister in any way he can. He tells her about prepping, lubing up, and going really slow. She says her anus is super tight and she has tried to put a finger in there but nothing. She tried and tried. She just couldn’t get anything up her tiny asshole. She just doesn’t want to upset her boyfriend and she would be grateful if Johnny could help her stretch her anus out. The boy tries to ignore her, but she’s just got that naked ass in his face. His naked stepsister begs him to help her, and he does just that. He starts by admiring her ass and telling her how good it looks. Then, he inserts his pinky and says she’s doing great. She barely moves from the doggy position she’s in when Johnny warms her up with his dick. He fucks her in doggy like a good stepbro. Soon enough, the girl starts getting relaxed on his dick. Johnny fingers her anus and sees that she’s ready for the whole dick. First, he slides the tip in and then slowly starts to move faster. Liz is amazed when she feels the whole dick going inside. He loves how his stepsister’s ass looks. He tricks the small-breasted girl into doing some naughty ass-to-mouth. Liz does as she’s told, regardless of the fact that that same cock was all the way in her rectum just a minute ago. Johnny rewards her by fucking her anus wide open in missionary and then in pile driver. When he eventually creampies her asshole, he fills her insides so deep that Liz can feel the cum in her belly. “You’re ready for your boyfriend, sis,” he says.