Managing other people's children

He's a brat & should never visit again.
But I do wonder why OP - and others on this thread - have balls in the house?
And allow them to be used indoors ?

You could tell your friend what he did and say you are happy to help but just be aware you won't be allowing those things and so will be telling him off if he does them.

Fuck that shit! Hope his parents paid for a few mirror!

I am a GM and there is no way I would put up with that behaviour from any child at any time. Through experience I have found that a lot children who are 'good' at home are nightmares in other people's houses. I do wonder if they are left to reek havoc no matter where they are.

You are not being unreasonable to set boundaries eg: no kicking footballs in the house or any other reasonable house rules. i would be kind but direct with this child. Eg: We dont kick balls indoors because its dangerous and could cause damage to things or people. If he said "well i do it at home" id say we dont do it here in this home ,so if you want to do that you can go home if you prefer?
It a safeguarding issue.
The ball kicking indoors triggered me a bit, some years ago my son had a friend like this boy. Kicking a ball around the living room ,asked him repeated politely not to do that ,he laughed and said he did it at home, suddenly he scored a direct hit on my antique overmantel mirror ,it shattered and the shards fell around him ,he looked like he was sitting on the iron throne game of Thrones style, I made eye contact with him and as calmly as i could said "dont move please" . He didnt and i cleared the way and scooped him up. He cried ,mainly terrifed his parents would be cross and relief he handnt been impales in think. I said thats why i dont like balls being kicked in the house and he never did again. I realised he hadn't had any boundaries at home and just had no comprehension of dangers .

I've had a few with the 'I'm allowed to at home...' talk. To which I generally call bullshit, as I doubt very much that any mothers would allow behaviour I have seen - it's the little buggers trying it on because they think you won't tell them off. The phrase, 'well, not here you don't' is often enough (because they're just pushing to see how far they can go).

The time two visiting boys threw spaghetti on my ceiling and then swung on, and broke, my washing line (I was busy with the baby) was a particular low point. They never did it again though

YABU to have him over again. Hell is other people's children!

I’d argue that by agreeing to look after the boy, OP has placed her son in ‘host child’ position. They are friends, this isn’t a random child.

But that's not fair on op's son. OP doesn't say they are friends, she just said they get on. If he wanted to host the boy in his own home, presumably he would ask to have him over. As it is, he's being pushed into this position because their mothers are friends.

I wouldn't think twice about disciplining if required, just as I'd expect my kids to be disciplined too. I don't think I've ever been told that my dds have misbehaved at other people's houses but they've always been very respectful of other people's homes & would never answer answer back to an adult

Just tell the parents that his behaviour is unacceptable, & he will not be coming to your home again.

I’d argue that by agreeing to look after the boy, OP has placed her son in ‘host child’ position. They are friends, this isn’t a random child.

If sitting quietly for 30 minutes is absolutely essential to OP’s child, she needs to limit his range of friends accordingly, both as guests and people he visits. He won’t always get his own way.

Of course you shouldn’t have your things wrecked by another child but expecting a child to have 30 minutes of quiet time when they excited at going to someone’s house isn’t realistic, they have come to play not quietly chat.

OP, I'd just say you can't have him again.

So your son, as host child, needs to compromise to make the guest feel welcome.
If you’re not willing to host a guest don’t. But don’t be a grudging, poor host.

Is he an invited guest whom op's son actually wants to host, or is he a boy op is looking after as a favour to his mother? If op's son didn't invite him, he doesn't need to compromise his behaviour.

You just need to consistently explain and set the boundaries for your home.
Tell him what you DO want him to do, so his brain pictures that. Ie rather than ‘don’t pull on the washing line’ where the idea is then reinforced of pulling on the washing line, ‘come away from the line’ or ‘hands off the line’ .
He will learn, he’s only 9.

OP isn't the parent. It's not her job to do all that.

But they’re all such precious little angels who do no harm to anyone or anything…we must wrap them in cotton wool & NEVER do or say anything that might in anyway upset them! Boundaries? Never. Consequences? None. Our little gilded offspring are the cutest, cleverest, most amusing creatures that nature has blessed us with…in other words little sods with parents who don’t give a flying fuck.

I emphasise. Dd's friend's mum told me that her dd was an asbo waiting to happen but there was no discipline in the house. One of the other kids had rotten teeth because "she refused to brush her teeth". 😯

If a child is in my care and misbehaves they get a telling off and consequences.

That said jumping on furniture, kicking drinks, trashing the garden and breaking things means they wouldn’t be invited back again.

that’s too much

Of course you can discipline someone else's child in your home! Your house, your rules!

Remember that children are very adaptable. As soon as they start school, they are taught and can understand that different rules may apply at school compared with at home, and different teachers sometimes have different rules. They absolutely can adapt their behaviours if they so wish. You just have to keep enforcing the rules. Consistency is very important.

If you can bear to persist with the child, you'd be doing him and his family a favour by reinforcing the understanding that rules must be abided by. Typically, try a warning followed by a consequence. "We do not jump on the sofas in this house. If you do it again, I'll take you straight home", and then follow through. He'll soon learn you're serious.

On the other hand, if you can't be bothered with the hassle, which is completely understandable and fine, just don't have him back to your house, and make sure you tell the parents why.

Can you take them to a park where the boy can run around and let off steam, without damaging your home?

I'm totally with you on ‘your house your rules’, especially re safety and breakages but in terms of activities, interests and food preferences you may need to compromise to accommodate a guest. e.g. your son needs half an hour of quiet, this boy needs to run around. Incompatible. So your son, as host child, needs to compromise to make the guest feel welcome.

If you’re not willing to host a guest don’t. But don’t be a grudging, poor host.

You need to speak to the parents and tell them no unless he agrees to adhere to your (very basic and fair!)rules. It's your house!

Dh said politely no to someone else’s child aged 10 in a shop on a birthday treat. She proceeded to have a huge violent tantrum. We and the other girls were absolutely horrified. Parents had been total panderers to her - they had created a monster.

If a child came in my home kicking footballs, breaking things, it would the last time they were welcome in my home. Sod that

There are 2 types of children like this. Ones who have no discipline, and ones who are so tightly disciplined at home that they go a bit crazy. DD1 has a friend who is the 2nd type, her parents are so controlling that when she comes to ours she relaxes and gets a very silly, running round shrieking, breaking stuff as she goes. It would be impossible to speak to the parents, they would never imagine her behaving like this I think and any criticism of their 'perfectly moulded child' is rejected as jealousy apparently.
Luckily that friendship has cooled this year so we don't need to have her round anymore, but I did feel quite sorry for her.

The 1st type don't get invited more than once to our house

I would text back and say you can’t have him. I would have told his parents when they collected him the previous time, to be honest-did you tell them all the things he’d done?

Of course you can discipline a child in your home! Surely that's a given. The adult who is caring for the child is in charge. I'd be upset if someone stood back and let my kid do what they want. If he kicks the ball it is confiscated, if he back answers he loses a privilege etc. Some kids completely take the piss and need firm boundaries, some are more cooperative. Some behave totally different in different environments so all the parenting in the world goes out the window. You need to set the tone in your house. All that said if you don't want to do this then you don't have to.

When mine were small, any child in our house has to follow our rules. And I made sure they knew I meant business when I told them not to do something.