One summer afternoon, when I was sixteen years old, I worked out with my barbell set and took a shower. Because I knew that my parents were going to be away until late in the evening, and because I thought my sister was visiting a friend, I did not bother to wrap a towel around myself, but walked naked to my bedroom. My sister surprised me, standing in the hall. "I'm sorry," I said quickly, wondering if I should run back to the bathroom, "I thought you were at a friend's house."

"She wasn't home, so I came back. I'm not sorry. I haven't seen you this way since we were children." I did not know what to do. My sister stood in the middle of the hallway, so I couldn't get past her. She continued looking at the part of me I wished I had covered with a towel. "It's gotten bigger," she said with a sly smile. This was embarrassing. It became more so when I got an erection. I felt my face blush to reveal such physical evidence of the fact that my sister was arousing me sexually.

She was also enjoying my predicament. "Look at that," she said bringing her hand to her mouth. "You don't need to blush just because you're naked," she teased. Then she instructed, "I'm your sister, so everything's all right. A boy shouldn't be embarrassed to be seen naked by his sister, even when his penis is pointing to her face." She giggled. "Besides, I think you're enjoying this as much as I am. A boy's penis gets like that when he's excited."

"Did you learn that from another boy?"

"None of your business," she pouted. Then she implored, "May I touch it?"

"You better not tell anyone about this."

"I won't tell. I promise. Please let me touch it."

I have to admit that I was beginning to enjoy the situation. I reasoned that I had not planned this, and that my sister was taking the initiative. Therefore, I was not guilty of sexual abuse. (If she was guilty, I did not mind, really.) Moreover, she was my sister. I did love her. I did not like to displease her. As the baby of the family she was somewhat spoiled. I feared her bad moods. I also feared that if I did not grant her request, she might ask another boy. Finally, and most obviously, I could not hide my desire for her. "You can touch if you don't tell."

"Oh goody!" My sister began gingerly to touch and squeeze my penis with her fingertips. "It's so hard," she said with a wondering tone of voice, "and so big." Without asking for my permission, she began to rub my penis. When I did not pull away she rubbed harder. I had never been like this with a girl before, but I had masturbated. This was better. My sister's hand felt soft, warm, slightly moist, and completely delicious. As I felt my climax coming, I closed my eyes. When it came, I experienced the longest, most intense, and most pleasurable orgasm that I had ever enjoyed. My sister squealed with delight.

When I opened my eyes I saw that my seminal fluid was on my penis, my sister's hand, and her dress. "A drop of that can get you pregnant," I warned. You should wash your hands before you touch your vagina."

"I know," my sister said, looking at her hand, and smelling it. She took my hand with her other hand, and said, "Come with me. I'll wash you too." She led me to the bathroom. After washing her hands thoroughly, she took my washcloth, got it nice and sudsy, and began to scrub my genitals. "It's all squishy now," she said.

"After a boy has an orgasm, and that's what I had when I squirted semen on you, it usually takes awhile before he can get an erection again," I told my sister. "Otherwise, I'd certainly have one."

"I see," she replied thoughtfully, as she scrubbed with enthusiasm. "Well, if you have another orgasm I will just start washing you all over again. I hope you're enjoying this. I sure am."

"It's kind of embarrassing," I admitted. "And it feels strange to be doing this with my sister, but yes, I'm enjoying it. That's why I got an erection and ejaculated."

"That's right," my sister said. Then she proceeded to rinse and dry me. She took much more time with each task than she really needed to. After folding my towel, and returning it to its rack, she playfully tugged at my pubic hairs. "You didn't used to have all this hair."

I turned to leave, but my sister said, "No, we're not finished yet." She sat down on the toilet lid for a closer look, put her hands on my hips, and positioned me to stand right in front of her. "This is truly amazing," she said. "Boys' bodies are so strange."

"I'm glad you think so."

She began to feel one of my testicles. "This is where you make sperm cells and testosteron-e," she said pronouncing the last "e" as a syllable.

"It's testosterone," I corrected.

"I'll remember that." My sister began to giggle. "My big brother is helping me with my sex ed homework."

"Better me than another boy."

"You sure are jealous, aren't you?"

"With a sister as beautiful as you I need to be jealous, and vigilant."

"No you don't, but thanks anyway," my beautiful sister said while affectionately squeezing and pulling on my now "squishy" penis. Then she rubbed my stomach. "You have such a nice washboard stomach. Every boy has genitals, but you have a strong and beautiful body."

"Thanks. I've worked for it."

"That's for sure." My sister stood up, put her hands on her hips, and said, "Well. You're nice and clean now. You may go to your room. I need to wash my dress before Mom and Dad come home." As I walked to my bedroom, my sister told me, "You look good from behind, too. You've got a nice, sexy butt."

When I returned to my room, I closed the door, and quickly got into blue jeans and a short-sleeved shirt. Then I walked to my sister's door and knocked. "Yes?" she asked.

"May I come in?"

"Sure." When I entered my sister's bedroom, she had removed her dress, but she had not put another one on yet. She was wearing a bra, panties, and sandals. Although my sister was only fifteen, her breasts were well developed and showed delicious cleavage above her bra. Her hips were beautifully rounded and full, although her waist was small.

"You've seen me naked." I said. "May I see you that way?"

"That's fair, but before we do it, I better put my dress in the washer." After a few minutes, my sister returned, closed and locked the door, and stood there, waiting. If she had agreed to show herself, I had expected her to take her clothes off, and show herself, front and rear. Then I planned to leave. Instead, she seemed to expect me to do the undressing. I took the chair from her desk, and sat in it. Without being asked to she sat on my lap. She began to feel my arms, which were fairly muscular from two years of weight training. "You have such strong and beautiful arms. Everyone at school knows that I have a strong and brave brother to protect me."

"And I will," I said, removing her sandals. I slowly ran my fingers over the parts of my sister's body not covered by her bra and panties, and said, "Your skin is as smooth and white as polished ivory. Your flesh is soft and warm. You are unbelievably wonderful to touch."

"You are unbelievably good at touching."

My sister kissed my lips, making a small suction sound. "When you kiss, don't suck in," I explained. "Just press your lips. Like this," I said, kissing her again. The second time she got it right. I kissed her lips, her cheek, her neck, and the tops of her breasts. She pulled my mouth back up to hers, and kissed me again.

When I tried to remove my sister's bra I had trouble unfastening it, because I had never taken off a girl's bra before. "I'll show you how to do it," my sister said. And she did. My sister shyly looked down. Her bra loosely draped her magnificent bosom. My sister waited for me to remove her bra. When I did, my hands trembled with emotion. I sighed with appreciation when I saw her lovely breasts with the delicious pink nipples that made me think of rose buds. "You've gotten bigger, too."