What would you do?

His parents need to get in the same page in parenting.

There is nothing you can do, sorry.

Your 1st sentence - he's 5 and Autistic.

Tell him off, remind him to use the toilet, then forget it. If he were doing that at the age of 15, it'd be more of a problem.

he does need to learn it, though because soon, as he grows, what is sweet behaviour in a toddler becomes very problematic when done by an older child and could lead to exclusion from school. perhaps that is an approach you could use with his mother - that he is rapidly reaching an age when this kind of behaviour will no longer be acceptable and will cause socialisation problems.

Problems with the internet meant the first part of above post seems to have disappeared.

In the first part I suggested the solution was Grandma's rules in Grandma's house, that is standard grandmother behaviour. It will need attention and time but he will soon learn that at Grandma's alfresco weeing is not allowed. You will also help him to learn what i put in the above post

I take it he is in school at 5?

I would use his behaviour at school as an opening to ask her how he is doing there, and say you want to reinforce the toilet training the school use.

Are you sure he understood your instructions as you know autistic children take things literally. At five years old I told my autistic grandson to eat his lunch in the garden. I later found him sitting among the flowers as that to him was the garden. Even though he is now 14 he still delights to take things literally. The other day I asked him what he made the time to which he replied "you can't make time".I am sure there was some misunderstanding in your grandson's case.

Yes, he is in School, and they have said he uses the Toilet without any problems when he is at School.
Up until Saturday when he did this he had always used the Toilet when he was here without any problems too, and after dropping him off back at his Mum's House, he apparently had a Pee on the outside wall of her House, even though she also has a downstairs Toilet that he could have used.

Yes, we have told him many times that if he is indoors and needs a Pee he must use the Toilet and that he can only Pee elsewhere if there is no Toilet available, so we know that he understands the instuctions because he has always used the Toilet before.
I am now wondering if this could be just attention seeking, or stress because he knew it was "Daddy's Visit Day" and on the previous Visit Day Daddy had upset him by shouting at Mummy, and after I had dropped him off back at his Mum's house, after I left, Daddy had been shouting at Mummy again which had upset him all over again.

he is rapidly reaching an age when this kind of behaviour will no longer be acceptable and will cause socialisation problems.

Have a chat about this with his mum.
Also explain Grandma's rules to your DGS.

Slightly confused about who was where when the shouting happened.
You could be right, though.

I had already gone home, and his Dad had stayed a little longer as there was something he wanted to discuss with my Grandson's Mother, which turned into an argument with Dad shouting at Mum, and during that argument my Grandson Pee'd on the wall.

I can only comment based on my own experience with my Nephew who is also on the spectrum. My DN could not (at that age) process complex information such as “you can do this if xyz is present but not if abc are”.
So in the scenario above if we told my DN you can only pee outside if there isn’t a toilet available, at that age his wee brain would only absorb the first part of the instruction without the condition, so he’d absorb you can pee outside.

The conflicting boundaries for this child will be problematic, if there is no consistency then no wonder he doesn’t know what’s acceptable: that would be tough for any child, never mind a child who is neurodivergent.

My advice to you OP would be to regularly remind GS remember to use the bathroom upstairs/inside/wherever similarly to how you would have when he was potty training. Also not to respond with anger or frustration (not that you’ve said you do, but I understand how trying it can be at times no matter how much you love them!). Using a calm patient tone and a simple sentence structure will hopefully parallel the way his teachers are communicating with him and might make it a bit easier to get instructions to stick with him.

Thanks Lolo81, Yes, I never get angry with him for it, but unfortunately his Dad does, and has gone as far as calling him a Baby because "Only Babies Pee outside, Big Boys hold their Pee and use a Toilet", I will try the constant reminders, because he only seems to forget when he is stressed, such as when Daddy has been shouting at either him, me, or his Mum.

Most autistic youngsters are usually extremely keen to obey rules, absolutely. So, if the rule is that you use a toilet for a pee, then that will be whast happens. Dothink that Lola has hit the nail on the head with giving this young child choices he is not able to make.
Does his father understand that autism can seriously effect the behavior of his son. Perhaps it would be a good idea for Dad to arrangeto do an on-line training course regarding autism. Sounds like HE needs more correction than the little boy.

Please keep the front door locked when GS is with you.Autistic children have a no "danger" issue.You're lucky he didn't wander off. I have an Autistic Neice,she was able to go out of an unlocked front door,crossed a main road and kept on walking,not while in my care I Will add! Can't bare to think of what could happen.
You should have a Frank discussion with the parents and reenforce the rules at your house.Autistic children need boundaries,routine and alot of it is "learned" behaviour.He may be getting mixed messages and not realising in general,people dont widdle outside unless there no other choice.

I would speak to my son for a start!

He gets angry with DGS and at least twice has been shouting at the child's mother.

No wonder the poor boy is peeing here and there.

Yes, Franbern, you are right, his Father refuses to accept that his Son is Autistic, or that Autistic Children's minds work differently to other children, I have suggested to him many times that some sort of course would be appropriate so that he can learn more about how to treat an Autistic Child, but he won't do it.
I know that during the 4 years that my Grandson was living with me he responded really well to a strict structured routine where everything was explained to him clearly and he was never naughty unless anyone started shouting at me or his Mum, but he no longer has this routine, instead of explaining why he needs to do something his Mum just says "You need to do it because i said so", which really just doesn't work for him.

Purplestar, the door was locked, and i had put the keys where i thought he wouldn't be able to reach them, but he had managed to knock the keys off the peg using a broom handle and had let himself out.

Knocking the keys down shows to what lengths he is prepared to go to make his point.
I think he needs more input by his Dad.
Do you know why your son is against educating himself about autism?

Your GS sounds very bright hybred1000

Your son is, as they say, in denial. Pretending his son is not autistic is not going to make it go away and what he is doing now could almost be described as child abuse, not allowing a child with a disability to have the opportunity for an education and access to facilities that will enable him to develop to the fullness of his capacity. If you haven't yet made these point s to him. perhaps you should, forcefully.

What you say of your grandson, gives the impression of an autistic child who would be capable, with proper parenting and education, to eventually make his way in the world on his own or with minimal support. it would appear that the behaviour of both parents is putting this at risk.

Your grandson is autistic and needs careful and understanding care. He may have mixed messages and is confused. If his father continues to disregard his sons condition then I fear things may get worse. I understand the father does not want to acknowledge his sons situation but but he does need some education and understanding so he can process what is happening. If that happens then that he will be in a strong position to support his son , recognize what autism entails and help his son develop and grow into a confident young man . I wish them well.

Namsnanny, I think the reason that my Son is so against educating himself on Autism is because he is in denial, because when he found out that he was going to be a Dad he envisioned having a "Normal, Intelligent Child", (His words, not mine), and he sees Autism as some sort of "Imperfection", we have tried to educate him to the fact that Autism does NOT mean Stupid, and that just because his Son is Autistic does not mean he can't achieve whatever he puts his mind to when he grows up.
My GS's Autism is caused by a Chromosome Deletion, passed on to him through his Mother, and his Mother has Learning Disabilities as a result of her Chromosome Deletion, so my son thinks that the problems we are seeing with my GS are due to the Mother's Learning Difficulties not because of his Autism, and that these problems can therefore be "solved" by what he calls "Proper Parenting".
I think this is also compounded by the fact that my Son was recently told that he also has Learning Difficulties so he wants my GS to be "better than him".
My Son just doesn't seem to be able to see that his Son is a Bright, Happy, Intelligent little Boy who just wants his Dad to love him for who he is, like the rest of the Family do.

M0nica

Your son is, as they say, in denial. Pretending his son is not autistic is not going to make it go away and what he is doing now could almost be described as child abuse, not allowing a child with a disability to have the opportunity for an education and access to facilities that will enable him to develop to the fullness of his capacity. If you haven't yet made these point s to him. perhaps you should, forcefully.

What you say of your grandson, gives the impression of an autistic child who would be capable, with proper parenting and education, to eventually make his way in the world on his own or with minimal support. it would appear that the behaviour of both parents is putting this at risk.

I totally agree M0nica, and I have tried getting these points across to my Son, but he won't listen to me.
And yes, both Parents are putting him at risk, my GS was, until recently, on the Child Protection Register, and then under Social Services as a Child In Need, and he kept telling the Social Worker that he wants to come back and live with me, because I understand his complex needs, he responds to me in a way that neither of his Parents are capable of getting him to do because neither of them fully understand his needs, but instead of listening to my GS they simply said he had to live with his Mum and Maternal Grandmother and then they closed the case.