Is 9 too young to observe childbirth?

I have a son who is 9.5 who has been looking forward to having a brother for 9 years (according to him). I will be giving birth in about 4 weeks and I asked him months ago if he wanted to attend the birth. After asking a few thoughtful questions ("will there be a lot of screaming?") he said he would think more about it before deciding. When I mentioned it to my husband he says it's a bad idea and does not want him there. I still think my son should have a say *if* it won't traumatize him. How can I know if it might? He knows about how babies are made and isn't overly interested/mature when it comes to that topic. He's just a typical 9 year old in my opinion. Any feedback is much appreciated.

Of note: I will be induced and have an epidural. I don't scream during labor.

What about asking your OBGYN or your child's PCP? They might be able to give some good advice on the subject.