Stuttering is not an end all be all. The vast majority of children outgrow it. Yes It can be tiring to listen to a stutterer speak. I was in college when I met someone else who stuttered for the first time. And they had it MUCH worse than me. It was a slap in the face because I thought I had it worse. Did I get tired listening to them? Yes. Impatient? Yes. That was an important moment of growth because I took the time to evaluate my attitude and learn more about our shared speech disorder. Please take some time to read about stuttering and how it works. This is not something that anyone can control completely, it is not something that we even know the cause of entirely. It can be caused by trauma, doubtful in this case, or simply how the brain wired itself as it grew and developed. Secondly, If your son has a stutter as an adult He will be fine. You're projecting the experiences you saw onto your son without even knowing how his stutter will develop. He will have friends, romantic partners, work - but also he will face teasing, bullies, and people who think he is less because of how he talks IF the stutter persists. Again MOST CHILDREN GROW OUT OF IT. What matters is that he has a supportive, loving family who build him up. He will have good friends who don't care. He will find what works for him. Maybe look up some well known stuttering adults - Drew Lynch comes to mind. He's a comedian with a You tube channel whose stuttering is the result of trauma to his throat. What is most likely happening when he is excited, agitated, or his sister is interrupting him is that he is holding that all in his speech muscles. This in my experience can lead to more stuttering, but also the answer isn't as simply as telling someone to slow down or think before they speak. I support you in asking his sister to wait her turn before speaking so as not to interrupt him. This is good for both him and her; giving him space and teaching them both respect. Now, I normally would say don't ask someone to slow down when stuttering, but knowing how kids can talk giant run on sentences, perhaps when he is really excited it might be wise to ask him to take a calming breath - and do it with him. Just don't make the cause of asking him to take a calming breath the stutter alone. My grandmother will say that to me when I'm speaking at a normal pace and it pisses me off, always has. Look into ways to release tension from the body. Work on these exercises with him - separate it from the speech though. For example, make doing some tension releasing exercises part of an mid day routine or evening routine, not when he starts to stutter. The whole spending time with just him sounds like a wonderful moment for each child. Your wife was correct that speech therapy is something that needed to be looked at considering a delay. Was it necessary? No one will know. I agree that sometimes people jump the gun at delays and rush children into therapies. I'm not a parent though, nor do I have education. You got what sounds like a bad therapist and bad directions at the start. I think that's where the fault lies, if any, You trusted educated professionals and much like how we used to think certain practices were okay for correcting behavior, maybe the directions they gave you are outdated and more damaging. YOU ARE NOT A FAILURE. My parents had me in therapies - Yet I am still a stutterer. Do I blame them? No. Did they feel like failures? God I hope not. If he never pronounces some sounds 100% correct that's okay. Apparently I sound like I have a Boston accent despite living in the midwest US. I once got asked if I was from ENGLAND! Please do not blame yourself or your wife. THIS - Stuttering - HAPPENS. It's not your son's fault, not his sister's fault, not your wife's and not yours. Most children grow out of it. A small percentage don't. Neither parent stuttered, My speech wasn't delayed, but I developed a stutter before kindergarten. I was in speech therapy for years on and off through my school - I don't remember very much actual speech therapy, teased heavily (Porky Pig comes to mind) and here I am a 33 year old woman with a great job, a boyfriend, and I won't shut up. I worked at Walt Disney World in a front speaking manner, dealing with guests on the regular. Sure, they won't put a stutterer who can't control her speech out as Cinderella (And most of those face characters have acting experience which can help). I worked customer service at a big box home improvement store, answering phones and do the loud speaking paging. Did I have to develop a method to be able to do that? Yes, I would trick my brain that I wasn't on a phone. Once, I had a lady comment after I had helped her via phone on how 'brave' I was for putting myself out there. That made me feel more awkward and self conscious than anything. I'm not brave for talking, for communicating, for do my job. I just have a stutter, I can still sell you a generator. Where I currently work, I give tours on the regular and am a fan favorite. I speak with high end clients and my opinion is valued. I answer phones. I have talked directly with clients who have millions of dollars and all of them have treated me with respect and not once said anything about my speech. If anything, I have been asked about it simply out of curiosity. I strongly believe my parents cultivated a "Don't let anyone treat you like you are less" attitude. Your son isn't less. You're not less.