I have two children who are 4 and 6, both boys. I am divorced from their dad and remarried. Their father lives with his parents as well as his 20 some year old brother and his younger sister. Their 2 children, 13 and 4 year old boys, also live their. My husband and I have noticed some very disturbing activity between my two boys. We cannot let them be alone in the same room because they climb on top of each other and play with each others genitals and butts. Also, my 6 year old lays down and plays with his penis quite often and his teacher has talked with me about it. This morning I caught my kids in the playroom with my 6 year old's pants down and my 4 year old licking his butthole. I don't know what to do. I highly suspect that they are seeing inappropriate things at their dad's or that they are somehow being abused. Also, their father was sexually abused by an older brother as a child and his younger brother was accused a few years ago of sexually abusing a younger boy. He plead guilty to crimes against nature and did some time in jail but was not required to register as a sex offender so I was told that I could not legally keep my kids away from there. They wouldn't even require supervised visitation. I am concerned that it could be either their dad, his brother, or the 13 year old that lives there. What do I do? It makes me sick every time that I have to let my kids go over to that house. Someone help!