My Great uncle married a woman who my family called crazy. My Great uncle met her at the mental institution where he worked, they fell in love and married. My Great uncle was retired living on an old farm, so he and his wife would watch me. They also watched Mom's sister's children in the summer and after school. I was the only girl there, Great Aunt would have me practice kissing my cousins. I was the same age as the youngest cousin the other two were a year and two years older. She had us dance while she played records on a hand crank record player.
My great Uncle slept most of the day, he rarely came out of the bedroom. So we were left with this crazy woman. She would strip us down when we got dirty and give us a bath.
I was developing and my aunt noticed. She pointed out my breast, and by then my oldest cousin had pubic hair. When my youngest cousin ask about breast, my aunt drooped her dress for a full display. That included a touch and feel, then have my cousins touch and feel me.
She let my cousins finger her vagina to see how it feels. My oldest cousin was post puberty and his cock was hard. My aunt would let him have sex with her. She was older than dirt then, she thought it was cute when he came and his penis fell limp. Then my crazy aunt suggested I let me oldest cousin push his hard cock in me. She forced me to let him try, but he could not get it in me. Thank God there was no lube.
But That did not last, After weeks of attempts to enter me, He finally got is in. I screamed and that woke my uncle. He walked in the living room and raised hell. Told my aunt that she can not allow this.

A few days later my aunt was forcing me to let me cousins have sex with me. Eventually I told my mother and she put me with my best friends mom.

Just a note here, NEVER trust your children with someone who's nuts