Did this occur in your presence ? In my opinion it’s not up to him to discipline your child and certainly not by smacking. I would have a chat with your sister and her boyfriend and explain that you chose not to smack your children.

I’d definitely say something, that is not ok!

Explain that they completely crossed the line and it is not up to them. They should never lay on hand on someone, least of all a child

I don’t care who you are – no one is to hit my child or any child or any person.
If he is generally a good person and worth explaining the severity to, I would put in the time with him and my sister but if he has red flags, cut him out.

Would be livid

What did he snack him for? How long has he been with your sister? Two questions I would need answers too before replying to this. Not knowing the answers, I’m leaning toward telling him it’s not his place to discipline your child and in future he should leave it to you

Tell him its totally inappropriate and to keep his hands to himself!

I would talk with my sister and her boyfriend when that happened and make clear that that is unacceptable to me.

I would go ape shit! I rarely smacjef my own kids so would be irate if anyone else did

I would try my very hardest to refrain from smacking him!!

There are a lot of factors that could come into this such as l: is smacking your children part of their discipline from you… How close you are to your BIL, if you gave him permission to smack them etc etc etc… I’ll take the assumption that none of this is the case and I would be having a stern word with him. There is no beating around the bush, he needs to be told in no uncertain terms that his s ruins were not acceptable, he is not the parent of the child and has no right to lay a finger on them.

I would tell both your sister and her boyfriend that they are never to touch your children again, and if he or she does, you will report it to the police.

Me personally? I’d lose my ever loving nut. He and my sister would both be well informed of my opinion by the end of my rant. This happened to my child during a sleepover to my sister’s house. My child was being excitable, as they do when exciting things happen, and he yelled and smacked. Then they didn’t bother to tell me the next morning… I only heard. “X was good. No problems.” Wtf? I found out when X told me, and none of my children have been back to Sis since. To be clear… I don’t smack my children, so this was far worse than it may have been, not to mention the fact that Sis’ bf was not yet a staple part of my children’s lives at the time. It was most distressing for X, I did my nut. I suggested that Sis’ bf might like to go toe to toe with someone his own size, and see how he liked being dropped on his behind. Although the fact that said bf and I were in high school together, and he is now Sis’ hubby, might have made me feel more comfortable in my ability to speak to him like that, I fully believe I would have done the same with anyone. (I just might have been more nervous about it. LOL) Definitely speak your mind. If they know you know, and you say nothing… They’ll think you approve. Best of luck, and remember… Your child, your parenting style. End of discussion. HTH.

I could understand if he growled at the child to prevent a dangerous situation. There is not details of the age of the child. I have “smacked” a child in the process of pushing hands away from danger. Once old enough they have to be taught right from wrong – verbally and told why a thing is not right. If they persist after a few distractions and explanations there are other options such as making them sit somewhere quite for a few minutes. You also don’t mention whose home this was at. We were taught from a young age that the person whose home you are visitng has their rules. When you are told what they are you obey them. Our kids and other relatives kids have been taught the same. At some stage you can confiscate a favourite toy, especially if it is being used to break the rule.

No-one has the right to smack anothers child! EVER!
I personally don’t smack my own children so there is no way I am going to allow someone else to!
I would be having a stern talking to my sister & her boyfriend & making it very clear that NEITHER of them are to smack my child.

Tell him to never do it again! It us not up to anyone but you and dad whether bub us smacked or not. Never let anyone else lay a finger on your kids. Totally unacceptable