. and I knew she was now a fully aroused teen. I heard a noise and turned my head. Carrie felt my movement and sat up. Several feet away stood my othe... niece. My erection grew even more as I realized she had pulled up her own top and was now pinching her excited nipples with both hands. Soon one hand was in her hip-hugger bottoms and she was passionately stroking her moist slit. "Tammie, what are you doing?" I asked softly. "Watching," she said in a sort of definitive. I stood there, unable to make myself go inside.What if she already went to work? What if she wouldn't let me in?I still had to call Jim. I had to think up something and make it good.I saw the front door open and a man come out. He said, "Hey Kelly, you just getting back from a date?" I looked at him and saw he was a very handsome man. I also realized that he had mistaken me for my twin sister Kelly. I would have thought that by now one of us had changed enough so people wouldn't mix us up. My stomach seconded the motion with an audible growl, causing both of us to laugh.“Do you want a shower first?” I asked. “We have us all over us and it’s a bit sticky.”She thought that was a great idea. We got up and walked into Becky’s bathroom and she started the shower. We took turns with the toilet while we waited for the water to warm.“Katie told me you two did it in the shower last week while she was on her period,” Becky said as we were washing each other. “You really aren’t the student. " I smiled at her, "I'll try not to leave marks that will be difficult to explain." "Fuck," she moaned, "Yes, I want marks as a reminder that you and I were real, that I offered myself to you. That you taught me, and used me for your pleasure." I turned the key in the lock and paused. "Once you step inside, and I close my door, I will begin." Amber shivered from head to toe and nodded. I closed the door behind us and met Amber's anxious stare. My cock twitched as blood began to be pumped into.