My question involves a child custody case from the State of: Maine
My four year old child lives with me but his father has visitation rights. The visitation is not at set times but when mutually agreed on. He usually only has a day visit one day a month which is based on his own decision. We live in two different states but are only a 2 hour drive from each other.
My child went to a day visit with his father last month and when he returned 6 hours later peed so much that I questioned if he ever used the bathroom with his father. He told me he had not. My child is shy about asking where the bathroom is and doesn't always remember to use the bathroom without prompting as he's only four.
Today he went on another day visit with his father. When I dropped him off with his father I told his father that he had not peed recently and was unable to go when I took him to the bathroom so he needed to make sure that my son peed when he got to where they were going. When he returned to me he had peed his pants in the car on the way back to the meeting point. His pants, shirt, and coat were soaked in urine. His father handed me a change of clothing and asked me to change him. I was furious but I tried not to show this emotion in front of my child. I asked my son on the way home if he had used the bathroom while with his father. He informed me that his father had never showed him where the bathroom was and he couldn't hold it in any longer.
I feel this is borderline neglect as my son is only 4 and should have been prompted to use the bathroom while with his father and at the very least told to use the bathroom before making the hour drive back to our meeting point. My parents disagree with me and say that my ex is just an inexperienced father. I'm not sure how to handle this situation. Any and all advice is greatly appreciated.

