Due to a family illness, we needed a babysitter for our 4 year old son. His friend's parents (also a 4 yr old boy) graciously agreed to watch him while we went to the hospital. Upon returning approximately 2 hours later to pick up our child, the mother of the other boy said "you may want to check his underwear, some feces was found around the toilet." Our son has never had a problem making it to the bathroom. He wet his bed once after being potty trained and cried. He has never had another accident either at home or daycare. We arrived home with our son, I promptly checked his underwear and there was no evidence he had any sort of accident. I asked my son if he had an accident, he bluntly said "No". I asked him where the poop came from from. He said "Daddy, KidX pooped in the bathtub." I asked if KidX had an accident. He said "No daddy. KidX looked at me, screamed, laughed and pooped in the tub."."Daddy, he didn't even TRY to go potty." My son then informed me that kidx proceeded to pick up his entire bowel movement, squeal and smear it and finally drop it in the toilet. The incident had an effect on my child as he was in the tub with KidX at the time. I know I have to tell the parents, but I am not sure how to approach it. KidX has had NUMEROUS BMs, which I am beginning to believe are not accidental. Other parents have also called the child's parents, including one who said KidX put his hands down a girl's pants. I WILL NOT have my child exposed to this type of irreverant behavior. Any ideas on how I should approach the parents? For my child's sake I can end my friendship with them in a blink of an eye. How do I tell them that I don't think our children should play together anymore?