It's your birthday, and your parents have been hinting at what a special birthday its going to be for you. You wonder what that could mean. Maybe a car? A big trip? But when your mother sits you down, you think you must've guessed really wrong. She says its something both she and your dad experienced at the same age, something special about becoming an adult. When she takes out a big thick dildo, you think she's going to teach you about the birds and the bees! She can be so embarrassing. "Mom," you groan, "I had sex ed years ago...you don't have to like, explain the parts of a penis to me!" she chuckles, explaining that this isn't for educational purposes. Not like you're used to. She tells you that this is her favorite dildo, and today you're going to learn how to be a good lover. Your jaw drops. What?! She has got to be kidding...but she tells you no, she's very serious. See, she and her dad, and your father and grandma, they all did this at the same age. It's sort of a family tradition, she tells you. You always knew your family was weird but this really takes the cake... Your mom is fit, with big breasts and a round ass, tattoos and piercings. She's the cool mom, and you try to remind yourself of her free spirit. How maybe this isn't so beyond the pale, as she leans back and tells you to watch her fuck herself. Her pussy is wet and welcomes the thick toy easily, as she thrusts in and out. Your cock is rock hard as she starts to talk dirty. You can't believe this. She tells you to stroke, that your erection under your jeans is turning her on. Your boner. Straining against your pants. Is turning your mother on. What the fuck?! But you're too turned on to care. You start to stroke, watching her as she explains that since you're the oldest, it took a lot of talking with your father to decide what she'd teach you. She talks about your sister - how dad will help her when she's older - and about the differences in what she and your father wanted to show you. "See, he didn't think it was ok to show you anal...but this is about being a good lover! And that's what I want...so that's what we're going to do." You cannot believe your ears! You're going to fuck your mother's ass. You practically cum all over her when she says that, you want to cum so badly, but you take it slow, working into her tight asshole, letting her accommodate your girth as she moans and tells you to lube her asshole. Finally, you're in, your thick cock spreading her open as she begins to ride you, cumming with her ass full, begging you to fill her up. You let go, releasing a hot thick load into her ass, and watching it drip out. She tastes your dirty cum off your cock, cleaning you and playing with your cum as she smiles up at you