He curled his finger while it was buried in her ass and she jumped.“Yes yes yes!”“Tell me then!” Jason groaned. He needed her to say it. It wa... time to make her his permanently.“Yes, Jason I’m yours!” Karla cried out. Her fingers curled as she clutched at the wall of the shower. “Forever yours!”All of a sudden - just as it had with his mother and aunt - Karla began to spasm wildly as she came - completely overcome and overwhelmed by the process of what was happening to her. She sagged on her. I was angry with myself for not lasting longer because I wanted to fuck my sister all night long, but I knew I had two more chances.We had used up the last two condoms within about an hour, and it felt so naughty having to keep quiet while we had sex together with our parents only a few yards away, which made the sex even more dirty and fun. I was still horny so I gave her oral sex, and she was struggling to keep quiet which was such a turn-on, before she returned the favor and after I came in. I stood up and took off my pants, Donna stood up and said to Barry "Move into the middle", as he did he saw my 6" cock, as I positioned Donna I stuffed my rod straight into her waiting pussy, as I started to rock and roll her she was giving Barry some head that he'd never had before. After a while I said, pulling out, "Barry slide underneath her and put your cock in her.He looked horrified but Donna nodded, as he slid under her his cock slotted in and he started to fuck her, I said "Don't come. Her English Lesson involved saying the alphabet during oral sex. She did more than just recite the letters, she would sing The Alphabet Song against me and it would drive me insane! She would sing it slowly, with exaggerated mouth movement until she had me squirming all over the bed, or table, or stairs, wherever! It was incredible and she loved doing it to me! It got to the point she would start humming that song to me or reciting a few letters and it always gets my attention.One day, shortly.