The ice between us had broken and there was no secret now. It was a strange situation.From that day onwards we sisters would tell each other when we w...ere to go to his room or what happened there that night. During that month thrice he came in our room; one of us will unlock the stairs and he’ll just come late at night and take both of us, except on one occasion when my periods started that very morning when he was to come, so I sucked him off once and he came in my mouth. He took sis 3 times. She knew he was going to fuck her while she was tied.She hated to admit it but she was feeling quite excited.She wasn’t going to give him the satisfaction of knowing but she was really looking forward to feeling his hard cock slide into her.What she actually felt was him leaning down and his tongue probing into the rose of her arse.She bucked violently...” What the f...?” He was now pressing at the entrance to her arse and she hoped it might just be a finger but she knew that it wasn’t.His cock. I looked down at her flat little tummy as I slid back into her again deep enough that I nearly touched her cervix and wondered what that tummy would be like all swollen up with a baby inside. I wondered what it would be like to fuck her all swollen up like that too. “Faster, harder!” she hissed. “I want you to really fuck me, not play with me. I want to feel you cum inside me; that’s what really gets me off.”I started going faster, and as I did, the pillows came off the bed, her sexy legs. Standing in front of her, she looked really turned on and it was obvious I was getting a hard on. "Well I'll have to confiscate that one too," I said. I can't believe I said that, she could get me in a lot of trouble for this. "Ok!" she said, playing dumb. She immediately kicked off her shoes, pulled down her shorts revealing legs that were simply incredible, with well defined muscles and no fat, and a bright red thong. She turned away from me and bent over to pull off the thong. I wanted to.