A Lesson in Biology
Copyright© 2026 by Lubrican
Chapter 5
Coming of Age Sex Story: Chapter 5 - She wanted to be a cheerleader but her grades were too low. Summer school might solve that problem. But she needed a tutor to make sure. Her mom got a name from the school and he was hired. When they got to the biology tutoring, she wanted to understand the reproductive system. He was happy to teach her about it.
Caution: This Coming of Age Sex Story contains strong sexual content, including mt/ft mt/Fa Mult Teenagers Consensual Heterosexual Fiction Incest Mother Son Brother Sister Harem Interracial Black Male White Female First Lactation Masturbation Oral Sex Petting Pregnancy Voyeurism
Robin found her mother by the sound of crying, but the first place she had intended to look was her mother’s bedroom. When she got there her mother was curled up in a fetal position, sobbing. Aware that she was still naked, but unworried about it, Robin went and sat on the edge of the bed. She reached to put her hand on her mother’s shoulder.
“There’s nothing wrong with you,” she said. “Marcus told me what happened and it sounded just like what you told me was normal. I think about that stuff, too. Please stop crying. Nobody thinks you did anything wrong.”
“I almost kissed him,” groaned Molly.
“So? It’s not like that would be cheating on Daddy.”
“It’s what I thought about doing after I kissed him that would be cheating on your father.”
“I don’t care about Daddy. He did it first. He can’t complain if you do it, too.”
“With a teenager? And a black one at that? I’d get laughed out of the neighborhood. People would call me a cougar at best and a nigger-lover at worst!”
“Mom! I’ve never heard you use that word!”
“I’m sorry. I slipped back into my past. I never used that term but I heard it used a lot. It was the most hurtful thing white people could think of to say.”
“I don’t care what people call you. I just want you to know I love you and I don’t think you did anything wrong. In fact, I wish it had happened to me. It sounds like it would be so cool!”
Molly uncurled and sat up. She moved to sit beside Robin. Her mind had begun working again.
“How did you know what semen looks like?” she asked.
“Oh! Um...” Robin couldn’t think of any reason to give.
“When have you seen semen, Robin?”
“Mom,” Robin said, still unable to think of anything but the truth.
“I thought we were going to be truthful and honest,” said Molly. “I have been truthful and honest. Why do I feel like you have secrets? Have you seen semen on a date?”
Robin grasped at that like it was a life ring from the Titanic.
“He got excited and I told him no and he said I had to touch him and when I did, he made a mess all over the place.”
“Who did this?” asked Molly, “And why didn’t you tell me about it when it happened?”
“It was Jeremy Howard,” said Robin, picking a boy whose parents had moved during the school year. “I was too embarrassed to talk to you. I mean what teenager tells her mother that a guy came all over her hand?”
“You do!” snapped Molly. “At least from now on. Are we clear on that?”
“Yes, Mom,” said Robin.
“Where is Marcus?” asked Molly.
“I told him to get dressed and wait until we could talk to him more.”
“I’m not sure I can talk to him after some of the things I said to him while we were...”
“Masturbating,” said Robin, helpfully.
“Yes.”
“Can I ask a question?”
“Okay.”
“How did it feel? Did you cum hard? I mean did you have fun?”
“You can’t ask me things like that,” groaned Molly. “Where did you learn to talk like this?”
“Sleepovers,” said Robin, carelessly. “I thought we were being truthful and honest about things,” said Robin.
Her mother looked at her.
“Alright,” said Molly. “But this has to stay between you and me.”
“Okay,” said Robin, crossing her heart.
“Okay. Well ... I don’t quite know how to describe it but...”
“But?”
Molly sighed.
“It was the best orgasm I’ve had in years,” she said.
Dressed again, the two women went back out on the patio, where they found Marcus, also dressed again. Before they spoke to him Robin stopped her mother and whispered, “I like him naked more than I like him with clothes on. Don’t you?”
“You should like a man for who he is in his heart, not what he looks like on the outside.”
“I know. And I do like him for what he’d like on the inside. I just prefer to like him on the inside when his outside is naked.”
“That is the first step on a road that will end you up under him, with both of you naked, and making love. Mother Nature almost demands it when two people are attracted to each other.”
“Want to know something scary?” asked Robin.
“Maybe,” said her mother.
“When I look at him and think about what you just said ... it doesn’t make me want to run away. With the guys I date, when they want to go too far I don’t like it. It makes me mad, even. But Marcus makes me feel different. What just happened today is a good example. I cannot think of a single other guy I’d want to skinny dip with, including Daddy. But I loved it with Marcus.”
“Then you have a decision to make,” said Molly. “If you know where this will lead, then you have to decide if this is the right time in your life for you to let yourself be led there. I want you to imagine that you do become sexual with Marcus, and you get pregnant. You’ll receive cruel treatment from your peers. They will call you a slut. They will call you stupid. You will be shunned by girls you thought were your friends. Other girls will act like pregnancy is something they can catch by being around you. And men will look at you and know you’ve let one man have sex with you, so you should let them have sex with you, too.” She paused, to let that sink in.
“Is that what happened to you when you were pregnant with me?”
“I was married. People expected me to get pregnant. The only part that happened to me was all the men who looked at me and thought I should happily fuck them, too.”
“Language, Mom,” whispered Robin.
“No. With those men, the men who don’t love you or care about you, that’s all it is: fucking. Animals fuck and men can be animals. Human beings are the only animals who can think about making love, and not all men are capable of being able to do that.”
“Do you think Marcus is capable of that?”
Molly looked at her sixteen-year-old daughter.
“Baby, I am way too young to become a grandma. So if you think you’re going to find out about that, we need to get you on birth control.”
“I didn’t say I want to find out,” said Robin.
“Girls don’t talk about wondering whether the boy they just went skinny dipping with is capable of treating her well in bed; a girl like that is a girl who will be interested in finding out.”
“Do you wonder?” asked Robin, looking at the boy who was lying on a chaise lounge, looking like he was taking a nap.
“I’m married,” said Molly.
“Answer the question, Mother,” Robin ordered.
“All right. Yes. I’m mildly interested in him in a sexual way.”
“If you weren’t married, would you go for it?”
“This is not the kind of conversation I had in mind when I said I wanted you to learn things.”
“Answer the question, Mother.” Robin’s voice was mild but firm.
“I think I’d be interested in finding more out about him and finding out how he would treat me in the pre-sexual intercourse aspects of things.”
“You mean like during foreplay?”
Molly looked sharply at her daughter.
“I hope that you do not perceive what you do on dates as foreplay, Robin.”
“Not yet,” she said. She hugged her mother and while doing so whispered directly in her ear, “But I haven’t gone on a date with Marcus, yet.”
Molly disengaged herself.
“In that case, he’s mine. If your father divorces me I’ll ask him to be my boyfriend. You can’t have him.”
Robin laughed loudly enough for Marcus to lift his head and look at them. He turned on the lounger and bounded up as if he weighed nothing. He trotted toward them.
“Am I supposed to leave ... or what?” he asked.
“You look hungry,” said Molly. “We have food. Will your mother be concerned if you spend more time here?”
“My mother thinks I’m crazy for spending so much time alone in a white girl’s bedroom. She’s used to me doing crazy things.”
He didn’t mention that one of the crazy things he did was bed his mother and sisters regularly.
It was eight and the sun was down, but it wasn’t dark, yet. They had eaten what might have been called a light lunch if it had been noon, but none of them put a name to it. Their hunger was assuaged.
There had been very little conversation during the meal. Other than requests to pass this or that, and the occasional comment on how good things tasted, not much was said.
Finally, Molly wiped her lips with her napkin and leaned back in her chair.
“We need to talk about what happened this evening,” she said.
“If that means you’re sorry it happened, and you don’t want anything like that to ever happen again, then I don’t want to talk about it,” said Robin.
“Okay. I won’t say that,” said Molly. She looked at Marcus. “Marcus, if my daughter and I wanted to have more ... pool parties ... and if you were invited to them, would you want to eventually touch us?”
“Yes, Ma’am,” said Marcus, without any delay.
“Ooo!” said Robin.
“Would you want to touch us sexually?”
“Yes Ma’am,” he said again.
“My daughter is only sixteen and I’m married, Marcus.”
“Are you, really?” he asked. “Do you still feel married? Do you still feel like you don’t want to have any other man in your life?”
“Are you asking to be in our lives?”
“Answer the question, Mom,” Robin ordered, gently. “He has.”
“If your father never touches me again I’ll be relieved,” said Molly. “If he came to me with a smile on his face and an erection, all I’d be able to think about is the other woman, seeing him in exactly the same way.”
“So having another man in your life ... on some level ... might not be so bad?” Robin sounded hopeful.
“Let’s just examine this a bit,” said Molly. “Until today, the only things I’d ever said to Marcus were casual hellos and a few questions about how your tutoring was going.” She looked at her bare wrist, where there was no watch. “Now, in the last three hours I have stripped naked with him, masturbated with him, and almost kissed him. I think that’s kind of rapid, in terms of expanding our relationship. And I know he would do the same thing with you.”’
She looked at Marcus, who shrugged his shoulders.
“You both make me a little crazy,” he said.
“So now I want you to imagine the three of us, standing in a tight little circle in water up to our necks, masturbating like monkeys at the zoo, thinking about doing even more. The three of us. I mean you and me and him. That’s called a ménage à trois, Robin. It’s called a love triangle. Does that sound like the kind of relationship you want to have with him? We already know that it would be fine and dandy with the male. He obviously would wish to have a little harem. Would you want to be in a harem, Darling?”
“I don’t know,” said Robin, softly. “I haven’t thought about that.”
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