I started breathing a little faster as I watched while they began to rub on each other as if they were the only one's here; perfectly content in their building ecstasy, my two sweet horny little deviants. Rachel ran her fingers through Alex's hair and grabbed at his head as her other hand rubbed against his legs and groin. My son would shift the position of his hands once in a while, squeezing her ass, rubbing her back, grabbing her waist, and groping her tits.
I grabbed Rachel and pulled her away from Alex. She tried to turn her head to see me as I held her to me, draping myself over her to seal her arms to her sides. I felt her heart pounding through her back against my chest. There was a phenominal heat from her waist where my hands were resting and I fought an urge to lift her dress and rub her pussy with my fingers. My kids were both breathing heavy and both seemed to struggle with restraining themselves now in my presence.
Rachel soon followed my gaze as I stared at the newly developed bulge in my son's pants. I whispered to Rachel. "It's time." I then told Alex to take off his pants.
As his fully erect dong sprung to life, my daughter dropped to her knees in front of him and took hold of it. I could tell this was somewhat new to her. Whatever they had been doing before must have been dead wrong. Lust filled my daughter's eyes as she looked at it and felt it in her hand. I thought she must have been entranced by the heat if not the size.
"Honey." I said as my daughter began to move forward very quickly. She turned back to me as I came closer. "Not so fast. You don't have to try to shove it in all at once. In fact, it's better for both of you if you don't."
Rachel looked confused. Alex, on the other hand, had long since disappeared out into space, still breathing hard, waiting for whatever may happen next. I looked into Rachel's eyes and licked my lips. She understood immediately and slowly rolled her tongue over the tip of Alex's dick.
Alex shuddered, clapping a hand on his leg while his free hand gripped at the couch. One of his legs crawled around to Rachel's back like a hook. If he had been wearing shoes, it would have looked painful. But Rachel seemed to like the attention and she licked again and again.
It was definitely time. "Okay, honey." I said excited. "This may sound confusing, but I want to keep your teeth away from him. Pretend you're eating ice cream. Use your lips and your tongue but not your teeth. Understand..?"
Rachel nodded then parted her lips. She stuck her tongue out a bit as she placed her mouth against his prick. She gave another quick lick and then slid her lips down over the tip. Alex's moan sounded full of pain perhaps to untrained ears, but I could tell what he was feeling. He reached down to Rachel and placed his hand on the back of her head, stroking her hair and sometimes grabbing at it to add pressure.
Rachel would often look over at me. Not just me. My groin. I was clearly showing; and realizing that I was excited clearly made her happy. Her eyes would shift from watching Alex's expressions to watching me. She obviously relished the idea that she was pleasing us both in one way or another. When her eyes fell on me again, I brought my hands up together and did my best to signal her to stroke him. Again, she understood instantly and began to stroke his member.
Alex was shivering and twitching. I started to wonder if he was already cumming. But his moans remained unchanged. Rachel would moan with her eyes half-shut every once and again when Alex grabbed at her head. I didn't know how much more of this I could stand to watch before I lost it. I was watching my daughter give her first successful blowjob and instructing her how to do it and I couldn't help wishing it had been my dick in her mouth as I began to feel myself on the verge of cumming.
Impatience decided my next action as I placed my hand on the back of my daughter's head and pushed her further down Alex's shaft. He moaned heavily and his leg shuddered. Rachel tried to go down again but I stopped her. After a few more seconds past, I pushed her head down again. She then quickly began to bob back and forth as she heard Alex's breathing become a quickened pant of "Ah! Ah! Ah!"
Suddenly, Alex lurched forward and grabbed onto Rachel's head with both hands as he sunk down the arm of the couch and deeper into his sister's mouth. Rachel placed her hands on Alex's lower back as his cum washed down her throat.
I was struggling to calm down as I watched Rachel suck the last of the cum off of her brother's dick. She then turned to me and asked, "Did I do good, daddy?"
"Yes, baby. You did really good." As I felt the dampness in my pants, I turned and started walking toward the bathroom. I had some personal business to attend. I certainly didn't want to explode in my pants. I popped off a quickie at the toilet while imagining Rachel's mouth wrapped tightly around my cock.
As I walked out of the bathroom, Rachel ran at me and leapt onto me. At her age, she was just heavy enough that I stumbled a bit at the collision. She wrapped her legs around my waist and her arms around my neck as she rested her head on my shoulder. She looked at me with a little smile. "Do you really think I did good?"
I nodded and she smiled excitedly and set her forehead to mine. She then kissed my lips. I looked at her for a moment then. This was my little girl... no. She wasn't. She had transformed... and her brother and I had helped her do it. Watching her give head had changed me too. Now when I looked at her, I saw her for the ridiculously sexy nymph she was. So I kissed her back, ignoring the fact that she had only minutes ago guzzled cum from another man; my son, no less. I didn't have a choice anymore. I had to kiss her. I had to feel her. I had to have her... and I had to please her. I knew then that our story wouldn't end here.