My sister’s curiosity cost her dearly

In my early teens, we would visit my grandmother in a small town. My brother, sister and I befriended three girls, two were twins and their sister.
Our grandmother had a separate barn/garage with an attic area that was accessible by a pull-down ladder.
We were reaching the age of sexual curiosity and my brother and I, as well as another friend of ours, persuaded the three girls to go up to the barn for some fooling around. It started out just stripping and feeling each other. After that, we started masturbating and fingering each other. We hadn’t yet gone to the point of engaging in actual intercourse.

One afternoon, one of the girls older brother came looking for her. When he hollered for her, she yelled back and he came up to the barn attic and asked us what we were up to. At first, we didn’t tell him what we had been doing, but he seemed to know. Maybe he already suspected something and wanted to get in on the action with some younger kids. He pulled his pants down to reveal a rather large penis. He started stroking it and it grew even longer and thicker. Then, he told his sister to come over and rub it for him and she did. After she had rubbed his cock for a while, he told her to turn around. He pulled her skirt up and her panties down and he began dry humping her, pressing his shaft between her legs so that the end of his cock protruded from between her legs, almost appearing as if she had a penis. He then had each of us, guys and girls alike, stroke the exposed portion of his cock as he rubbed it between her legs. After this had gone of for some time, he took one of his hands and spit a bit glob of saliva into it and stroked his cock to lubricate it. With one arm wrapped around his sister and the other guiding his huge erection, he stood up and began pressing his cock against her anus. She was writhing and shrieking, “Jim, no! Stop it, Jim!” He managed to get the head inside of her then pressed hard and deep. She screamed, but he muffled her with one of his hands as he impaled her anally with his way too large penis.