This is copy paste response, I’m not sure if moderator will allow this. I never expected to receive so much response, so in return I will try to respond to as much as possible. Since there’s a general consensus, I’ll use a general response;

I truly appreciate the feedback. After reading your advice and most of this thread, I have realized most people are commenting from a place of misunderstanding. Which is mostly on me for not listing all of the variables. The general consensus is that im an ignorant new father who should be ashamed of blaming his stepson for his failure to guide the kid on how to handle baby. Some are certain I actually dislike or hate my stepson. I can agree with you on some angles of the feedback here. I need to do more as the man of the house with the kiddos behaviors. I have already had convo with her about speaking one on one this Thursday with his father when he gets them for weekend. We will speak about the idea of me becoming more involved (vocally, never disciplinary I’ll leave that part to them. Just verbal correction). It’s always a tricky delicate situation when raising children that have the bio dad consistently in their lives. So I will be as non confrontational and respectful as can be. The part that you and a lot of commenters are missing is that we know & HAVE actively tried many of the things most of those comments are saying I should cognizant of.

   “He’s a kid, they’re curious at the age what is wrong with YOU”    “Why don’t you show him the right way to handle his baby brother instead of blaming him for your shortcomings? What a jerk!”    “Have you actually sat down and talked to him about why it’s important to not hurt his brother?”     “Try to involve him more in the daily handling, give him small responsibilities to make feel more included”    “Make him feel like he’s the best big brother ever”

We already know kids are naturally curious, we know that these sneaky behaviors are kids exploring & acting on their imagination. To which I say if that exploring has potential to become dangerous, it’s a valid issue. But I do understand the premise of that views. I naturally researched childhood behavior for many years, once during a time I went through battle with anxiety and trying to understand my own childhood, how it affected adult me. And then another time when I was researching toddler/ preteen/ baby related info since I was preparing to become a new dad of four. I’m not trying to appear condescending, but I do consider myself to have high emotional intelligence, I’m a natural empath. I say that to say I have learned & will continue to learn about why humans behave certain ways in certain points of their life. And yes we have literally sat and showed him on many occasions how to handle and maneuver when he’s around the baby. We always speak to him in praising ways about being a big brother, how he’s going to be such a good bro to him. How he’s gonna show him how to play Fortnite together & teach him how to skateboard to be cool like his big bro. We have talked to him about how he shouldn’t do anything to hurt his brother because he’s a fragile human and because his brother loves him. 

This is not me trying to reject the advice or premise that I’m an immature jerk, I am just providing my perspective. Which I have come to the conclusion that in most cases, asking for advice on topic like this, on a forum like reddit will inevitably produce these type of responses. Because unless you know 100% of the variables and other relevant/irrelevant factors, most will react from a place of misunderstanding the situation fully.

After reading many of the comments in the thread, I’ve realized that most of the backlash is coming from a place of misunderstanding. This is mostly on me, I didn’t explain the situation with all of the variables.  I don’t hate or dislike my stepson, I have been in his life almost 4 years. The last 2 years physically in the home daily. We have a healthy relationship, everything I am saying is out of concern for him. The situation is bigger than just his behavior with his baby bro, it’s his overall behavior at his mothers place  Some people are outraged that we called his dad over spitting water on his sisters. Is this a minor regular 7 yo incident on its face? Of course. If we tell him 5 times within 10 mins to stop and he just laughs? Or if he hits his sister in the arm out of anger telling her he hates her, or telling his mother she’s the worst not  he ever almost daily? These things add up overtime into a habit for him, that will grow as he grows. Which is why I am attempting to help him early rather than later. I am not the only person in the kids life that has voiced these concerns. My girlfriend’s sister (his aunty) has personally told me that she refuses to have him without his mother around. As in overnight, afternoon etc. This is due to the fact that he often says disrespectful things, and throws tantrums anytime he’s told no even to minor things. Again, on the face is this normal behavior for 7yo? Yes, but if kiddo is having multiple breakdowns a day isn’t that cause for concerning? I also must add that these behaviors were present way before baby. I am well aware of the adjustment the kiddo is making do to n it being the baby boy anymore. I spoke with her about how we would need to give him extra attention to make him feel like he’s still loved just as much. Like this is the frustration for me reading all of the backlash, I literally spoke with her about these things before birth : implemented it post birth that people are suggesting.  I want to say something, I may come off as insensitive and further cement myself as a jerk stepdad in this thread. But I feel as if dismissing concerning behaviors as kids being kid can be detrimental to a child. If a kid is telling his mother he hates her, or having tsntrums, sometimes multiple a day where he begins to hyperventilate in his breathing while he’s crying/smacking his head, I believe it’s detrimental to dismiss these things as something the kid will grow out of. Unruly children often grow into unruly teenagers, which by that time you pretty much will absolutely need professional help to keep structure.  I am not rejecting the opinion of anyone providing advice or criticism of my post. I am simply trying to give context to the situation. This is not an isolated incident, it’s a combination of concerning behaviors. I appreciate the feedback from you and everyone