I know it’s none of my business buuuut….

Call Steve out next time he says anything out of order. Just say 'Whoa that's not right saying that' Tell your Nephew 'it's ok to cry if you feel upset, lots of men cry sometimes' Let it be known you don't always agree with what Steve is saying/doing. Also if he counts to 3 & your Nephew looks scared, ask his 'Are you ok, you look nervous why is that?' keep an eye on things when you're with your Sister & her family & see if there's a change in your Nephew when Steve is around. If there is & you're worried have a chat with your Sister letting her know your concerns,

I would avoid criticising, because you have no power and you need to avoid alienating the parents. I would concentrate on being a good aunt and trying to establish a routine of taking DN for sessions of water play or swimming, which will give his mother a break and give you an excuse to strip him and watch for bruising. Take photos of any damage that you see. Do not question him, just say something sympathetic about being sorry if he has hurt himself. Gather evidence, get the child confident to confide in you, or hopefully put your mind at rest.

I'd get a conversation going with Steve about trans kids in schools and drag queens doing storytime... I think your sister might see his true colours then and hopefully realise what he's like. His attitude towards males not being allowed to cry is very concerning. ADHD kids can actually be very conforming out of fear (although I'd suspect ASD in there too). The way he's handling him is what I would consider emotionally abusive. He's getting him "hyped up" then telling him he's in trouble for doing so. The suggestion that this might need mentioning to Safeguarding at school isn't that far off the mark and is probably a good idea to get the behaviour documented.

Before I get "mumsnetted" to death... There is a huge difference between a healthy attitude and violent bigoted disgust. You may all have views on the subject but that isn't what's being discussed here.

I think going straight to assuming abuse is excessive, it's unpleasant but nothing the very overstretched social services team needs to be informed of. Cases of injury and death are very publicised but also very rare.
Given some of the advice practically every child would be taken into care- which considering the average outcomes of care is not what anyone should want.
Even homes which are far less than ideal are hugely better than being in the care system.

True, they will not get involved if it's verbal/emotional abuse. It's not even illegal to torture a kid that way, but it should be.

I would speak to the schools safeguarding lead so they can keep an eye on him. I would not contact Social Services as despite what some people are posting, this does not meet the definition of abuse. It comes under parenting you and I, and many others would disagree with.
Can you offer to have your nephew to stay over some holidays to give him time with a loving family?

The homophobic comments are definitely wrong but SS won't get involved due to them. . I was just asking OP to clarify what her concerns were regarding the rough housing being too rough and why she felt the child was frightened.

This, nearly every week you hear of a child being abused then killed by the bf.
As some posters have said see if you can spend some time with him/take him out so that you can judge the situation.

Spend more time with your nephew and address Steve directly if you hear such homophobic comments again

I don’t like the gay boy bit but I think you should mind your own business. His mum’s happy with his parenting and he spends 50% of his time with an involved dad. It’s their issue not yours.

This type of thinking and advice is dangerous. The news is littered with instances of step parents seriously hurting over prolonged periods or killing them, after LOADS of people voiced concerns about being uncomfortable or witnessing thigns that made them uneasy.

OP, you have 2 sensible options here:

1. Send a message to this poor boy's school so that teachers can keep a closer eye on things.
2. report to social services that you have concerns.

I'd be doing both.

there have been too many horific cases recently to do anything else here. REPORT IT. don't approach your sister, you've already tried it, and she's shut you down. you need to act to ensure more eyes are on this child. what happens if this "rough housing" (I hate that term, he is not an adult playing rough with an adult) goes wrong???

I would be really unhappy too- especially with the gay boys comment and the fact he has obviously taken over discipline, but as you say it is none of your business- all you could do is have a word with your sister, but as she is very private, and her comment about discipline, I don't rate your chances of getting through to her- she'll find out, in the fulness of time, most probably.

psycnet.apa.org/record/2018-47074-001?doi=1

Wow, do you listen to the news? Have you seen children killed by stepparents whilst their mothers stood by and did nothing, or actually said “ he’s better behaved now”. This is a dangerous situation for this child and you’re condoning this man’s behaviour. It’s totally not normal for a five year old to be called names and respond immediately to a count of one. It’s people like you who say, I was minding my own business, that allow people to get away with abusing or even killing children!

Big red flag!!!

He thinks he’s the man but what he is is abusive and your sister is turning a blind eye for selfish reasons. You should keep an eye on this situation. He is your nephew so it is your business.

That sounds unhealthy/dangerous.

This is good advice.

Homophobic verbal abuse is not a "firmer hand." Steve is the one who needs to learn boundaries. There is no way to spin what he is doing as appropriate discipline.

That child is very scared of that adult I think. It's easy for her to offload unruly son onto him now. But be careful.......

That would be a bundle of red flags for me too. Nothing about that is ok.

It is your business. Trust your instinct. Too many abuse cases where the mother's partner (not the natural parent) abuses a child. Keep a close eye. Visit more often. Don't look the other way. Report it anonymously if required.

Adding my voice so you can see how many of us believe your instincts are sound, OP.
Talk to DS, bio dad or the school, and keep an eye on the situation.
The gay/girl comments are vile. But the control he has over the little boy is arguably more sinister.

OP didn’t say that. The words used were “over hyped”.

What news about step parents, please?

1.You have to sxplain why something needs to be done or not done and why and actually get down to their eye level. Yes, I had to do that regularly with my two NT children, just because a child is NT doesn't mean you never have to explain things to them!
2.You also have to make sure they run around every few hours and on the whole put more into raising your child than a nt child. Shockingly NT also need regular exercise or it can affect their behaviour. My NT kids certainly had to get out and about and burn their energy off daily or they would have been climbing the walls at home.
I am not sure if you just gave really poor examples but your points could refer to NT/ND equally.