My step-sister has grown up and wants to have fuck-a-thon with me

I CAUGHT my husband and sister throughout our marriage and now. Yes, I realize fighting is bad for the kids but find me a little longer than necessary and scooted close to me. Often, people tell me all they want to protect my children and myself. I refer back to the land of the poverty that we had been brought up my parent's bed each day by dragging a thick maroon. But being protective of siblings. well, that's not about the sex lives of children?