Sister Competes With Jealous Sister To See Who Gets To Have Sex With Their Father. What Is Incest? Incest is when two or more people that are closely related participate in sexual activities with each other. People that are closely related have the same DNA structure as each other or a lot of similarities can … Continue reading If Incest Was Not A Thing Then Maybe Down Syndrome And Disabilities Would Also Not Be A Thing In Today’s World. The Creation Of Certain Down Syndrome, Certain Disabilities And Certain Mental Disorders Are Only In Today’s World Form Participation In Incest.