TMI warning ⚠️

TMI kids molesting kids. Am I over reacting?? I have a 4 year old and a 10 year old cousin. My cousin stayed the night with us once earlier this year and as I was putting my 4 year old in the bath he came from the bedroom and started touching my sons butt. I told him to never do that again and then I talked to my husband about it. He agreed that it was strange that he went out of his way to follow us into the bathroom and do that in front of me so we agreed that our son will never be around him unattended or stay the night. He’s also done other things such as peeking into the bathroom while my son is peeing. Well tonight I was admitted to the hospital and my husband works over nights and can’t leave work so I had to leave my son with my mom and she’s staying the night at the family members house where the 10 year old lives. I called to check on my son and heard my cousin say “I call dibs on sleeping with (my sons name) tonight” and it made me even more uncomfortable with the fact that my mom is staying there with them tonight. Am I overreacting? How would you feel? I’m freaking out. Idk what to do I’m thinking of just leaving the hospital