yes

John was still on his back his limp cock is still wet from his cum and his mother's pussy juices. His mother had left his room in a hurry and the door remained open.
He knew he had to close the door or cover himself up.
He looked at the door again and saw his sister Kelly standing in the door way looking at him.
He was on top of his blankets so he could not use them to cover himself.
He watched Kelly step in to his room and close the door behind her.
She walked over to his bed and looked down at his cock.
"I just saw mother come out of your room she was naked and there was white stuff on the inside of her legs, Did you just fuck our mother?" Kelly asked him.
When he did not answer Kelly touched his prick. She lifted her hand up and looked at the palm of her hand then she turned her hand and showed to john.
"Looks like cum to me and smell like cum." Kelly licked it and the said "Tastes like cum and pussy as well. You did fuck our mother."
John said "The pussy flavour is proberly on your own fingers from fingering yourself. Why dont you suck my cock and double check?"
Kelly gave John a strange look before kneeling down and taking John's cock in to her mouth.
She licked and sucked his cock it got hard. Kelly stood up and said "Yes I can still taste cum and pussy all over your dick. Then she turned to leave.