I stood awkwardly in only panties and that silly necklace and let her grope me. "You like it?" She seemed genuinely surprised."Sometimes I dream of yo...u doing it," I said without hesitating. Then I had the thought, "Did I just say that out loud?" I thought you didn't want to mess around with me?" I didn't say I didn't want to. I said I was afraid of being caught." So, you do want to?" As she asked this, her hands drifted down my tummy and I felt like hummingbirds exploded inside me.I nodded. " I said shyly. "Come and get it," she explained as she held it out to me. "What's wrong, you can show my sister and yet you can't show me?" She said. She could see that I was trying to be modest about my nudity. I placed both my hands front of me to cover myself as best as I could. "There is nothing vulgar about the human body. Vulgarity is a mental creation. So don't be ashamed that I see your body, if it makes you feel any more comfortable. I'll do this," she stated. ’ Her smile became even brighter as she stepped into the shower. The water started to bead on her breasts as she closed the door. The sound of the door closing made me hornier than ever. The two of us were in the shower, after such great early morning sex made this seem so special, so intimate. I was hard and still stroking myself, as this realisation flowed across my distracted brain, I abruptly removed my hand. ‘Don’t stop. I like watching you. Please carry on darling.’ She hugged her naked. My cock hardened quickly as she put on a long T-shirt covering herself. My penis was stiff and I thought I was going to cum without touching myself, but I grabbed my stiff rod and pounded it until I shot strips of cum on my d****s. The sudden appearance of her naked boobs went through me like a lightning bolt. A couple weeks went by. I kept an eye on their bedroom. I caught glimpses of them periodically, mostly dressed. I was sitting on my back deck enjoying a drink. I saw the twins come out.