I'm probably not the most considerate brother in the world - my sister is two years younger than my 15 years and can be a real pain in the ass - but I do care. And that's why I stopped when I heard quiet sobbing from inside her room on my way to the shower after running one summer morning.

I knocked gently. "Kit? Are you ok?" I heard a gasp, then a few seconds later, a shaky, "Go away, Mike. I'm fine." She didn't sound fine to me, so I cracked the door open and stuck my head in. Kit was lying on her stomach on her bed, tears as obvious on her face as the shock at seeing me there.

"MIKE! What are you doing? Get out of my room!"

"Look, Kit, I heard you crying in here. If you want to talk to me about it, I promise it won't go any further." Thanks to our father, the psychiatrist, everything emotional had to be talked about in our family.

"It's not something you can help me with, just go away."

"OK, Sissy, but you know where to find me." I closed the door and went down the hall to my room, hearing her yell, "DON'T CALL ME SISSY!" behind me, as she always did. "I wonder what's eating her?" I thought to myself. "She was all bubbly this morning when she headed to the park. She probably had a fight with some of her friends." I shrugged it off and stripped for a shower.

While I was showering, I thought about how much Kit had changed in the past couple of years. She had grown from a flat-chested 11-year-old tomboy into a sexy 13-year-old. Her tits were only plum-sized, but they looked bigger on her thanks to her small frame, and her hips and bottom had rounded out very nicely. She'd started growing her hair out, and now it was shoulder-length, hanging in a glistening black curtain when she brushed it, which she did religiously every night. The dark hair offset the startling blue color of her eyes. Sisters had their drawbacks, but at least she provided some eye candy to keep my motor running... not that it takes much to keep a 15-year-old boy's motor running.

Showered and refreshed, I entered my bedroom with a towel wrapped around me, dropping it as I closed the door. A small sound made me quickly look up and realize that Kit was sitting on my bed, with eyes as big as dinner plates. I quickly turned red, grabbed the towel and blustered, "Kit, what the HELL are you doing in here? You know better..."

Kit was even redder than I was and stumbled all over herself apologizing. "I'm SO sorry, Mike, I knocked and just wanted to talk and when I saw you were in the shower I just decided to wait and..." She ground to a halt, covering her face and bursting into tears.

My brotherly instincts, such as they were, took over for the second time in a day. I arranged my towel as best I could and sat down next to her, putting my arm around her. "Sissy, I'm sorry I snapped at you. You really startled me, and maybe embarassed me a bit, too. You know I don't mind talking to you." I gave her a one-armed hug, pulling her to my bare chest.

She took her face out of her hands and rested it on my chest. "Don't call me Sissy," she said automatically. Then she sighed. "I know, Mike. I thought about your offer to listen to my problem and decided to take you up on it. I should have waited outside until you were done." She didn't seem to be in a hurry to take her head off my chest, so I snuggled my hand around her waist and gave her another little squeeze. In response, she brought her hand up to my chest and ran it through the little bit of chest hair that I could boast.

The act seemed very intimate... more intimate than my adolescent hormones could deal with, in fact. The towel in my lap start to rise.

I pushed Kit away abruptly, embarassed all over again. Apparently she didn't realize what she was doing to me and looked at me, hurt and confusion apparent on her face. "Ummm, Sissy, what did you want to talk about?" I said, trying to draw her onto safe territory.

"That was nice, why did you push me away?" She said, scooting closer to me. She put her arm behind my back and gave ME a little squeeze, resting her cheek on my upper arm. I could feel her braless right breast on my left side, and believe me, it wasn't helping my situation. I broke out in a cold sweat as my cock reached full mast in a big hurry.

"Oh!" said Kit, finally noticing my towel. She took her arm from around and stifled a giggle with her hand. "I guess it was a little TOO nice!". She looked me in the eye and said, "Wow, bro, that's really impressive."

I cleared my throat and said, "Look, Sissy, it just happens to guys, we can't help it." She eyed me appraisingly. "Sure, Mike. And don't call me..." she sighed. "Whatever."

Her face got more serious. "So let me tell you what happened in the park today."

"I told Dad that I was meeting Angela in the park, but really I was meeting Chuck Sanford." Chuck was a boy about Kit's age. "I think he's really cute and was hoping something would happen." She sighed and went on. "I guess something did, but it's not what I wanted." I felt the blood start pounding in my temples as I thought I figured out where this was heading.

"Sissy, if he hurt you..." I said, balling my fists in anger. My erection was forgotten.

"No, no, it's nothing like that. He didn't hurt me. Well, at least not physically." Mollified, I sat back to listen some more.

"We found a spot in the woods with nobody around and started making out. He put his hands up my shirt, and it was feeling pretty good. Even though he was rough, I was into it and it was OK." She gave me a sidelong glance. "Are you ok talking about your sister's sex life with her?" She gave a short laugh. I just nodded at her to continue.

"Well, I decided I wanted more, so I put my hand in his shorts and felt his cock. It was hard, of course, and he really seemed to like it, so I unbuttoned his shorts. He did the same to me."

"I started jacking his cock." I must have had a question on my face, because she laughed and said, "No, I'd never done it before, but the girls talk in the locker room and at slumber parties. He didn't seem to be complaining, so they must have told me right."

"Anyway, he had his hand down my pants and started feeling around down there. It was pretty obvious he didn't know what he was doing, so I stopped and stood up to take my pants down for him. He was sitting on the ground, watching me undress."

She stopped for a second, staring at the floor. "Then he scrambled to his feet and said 'Jesus, Kit, you're a fuckin' freak! You have a COCK down there!'. He buttoned up his pants in a big hurry and ran off." Now she was crying again.

I was stunned. "He said... he said WHAT?" I stuttered. "Sissy, you are 100% girl, I have seen you naked enough times when we were younger to know that for a fact."

She said, "Look, you saw me naked when I was younger. I really AM a freak. I don't have a cock, " she gave a kind of watery sob, "but I have..." She stopped. "Well, it's hard to describe." She looked up at me. "Can I show you?"

It took a second for that to register. "Umm, Sissy... you want to show me your, err, privates?" She just looked at me tearfully. "I don't think there is any other way to get you to understand," She visibly calmed herself and said, "Look, I would go to Mom, rest her soul, but I can't." Our mother had succumbed to cancer two years earlier. "If I have to choose between you and Dad, I'd rather talk to you. Dad says we need to be open, and he'd try, but you know he's a prude about nudity." She looked hard at me. "I really need to know if I need to see a doctor or something. Or if I'm just going to be a freak for the rest of my life. Or maybe I just need to hear someone tell me I'm 'normal', whatever that is." Tears started forming in her eyes again. "Please, Mike, I really need your help."

"OK, Sissy, show me what you need to." My big head managed to make me sound reluctant, but my little head was definitely intrigued by the possibilities.

She said, "Thanks, bro.", and leaned over to give me a quick peck on the cheek.