When I was a kid, I, my younger brother and younger sister and three of our friends were doing some innocent sexual experimentation in the loft of our grandmother's garage with one of our friends' older brother discovered what we were doing and decided to join in and educate with regard to sex.
We were just fooling around, doing nothing more than touching each other and some kissing. When "jim", one of our friends' older brothers found out what we were doing, he decided to join in. At first, he had us all, boys and girls alike, rub his penis until he was fully erect. His penis was huge. Very long and thick. He had his little sister stand naked in front of him with her back to him and he would move his penis back and forth between her legs in such a way that when he had it pushed all the way forward, it almost looked like she had a penis. He would have us all rub it and eventually put our mouths on it and suck on the head of it as he moved it back and forth between her legs.
After he had become sufficiently aroused, he did something I cannot forget to this day. After having been stimulated sufficiently by all the aforementioned activity, he wrapped one arm around his little sister and with his other hand, positioned his erection at his sister's vagina. We wanted to do something to help her as she screamed in agony as he raped her virgin hole. Using both arms, he literally bobbed her up and down on his shaft. It was just a couple of minutes until he climaxed inside of her. When he was done and he let her go, she literally fell to the ground, blood and sperm oozing from between her legs.
After he had raped her, he forced me and my little brother to do things to my little sister that I would never have imagined doing. I don't know that I can even go into detail as to the things that we did to her and made her do do us.