Help me, please?
I second PP. I would be honest, and say something like, "when you were born, based on the information we had then, we believed that circ was the right thing to do for you. By the time your brothers were born, we had new and better information, and we decided that we would not circ them. I regret that you had to have the procedure, and if I could change it, I would. However, the good news is that you have had no complications from your circ, and you are perfectly healthy."
See where he goes from there. I think that if he shows regret or anger, you should acknowledge them, apologize (which you did), and then move on. You could always sugggest that when he has sons, he can leave them intact, too.
HTH! I am sure that this was an awkward conversation. Hang in there, and keep us updated. We'll be happy to try and help!
"Doctors can do amazing things to help sick people because they are always learning and using new information to improve their treatements.
When you were born lots of doctors thought it was best to take away the skin at the end of the penis, and we believed them. It happened to very many boys your age and even more boys in the past. Nowadays most doctors understand it is best to leave boys the way nature made them.
I'm sorry for what happened to you, but if you like you can painlessly expand the skin you have so it acts like a foreskin and protects the end of your penis."