I agree with you. no interuptions are tolerated, unless. the house is on fire or there is blood pouring out of someone. Your child and all children, need to master this by kindergarten..
It is one of the signs your child is ready to attend kindergarten.
It is just like being able to sit and listen to a story with out talking.. that is another skill they will need.
Raising thier hand is a good way. to get your attention without dispturbing the conversation. . Or maybe if it is not a grown up topic situation. They can stand quietly until you stop for a moment.
It takes practice.. it is also good to show an example every once in a while..
You play your son, while he is talking to dad, or to one of his friends.. see how he feels. Make sure you say pardon me. or excuse me, to your husband.. and let him do this to you.
Let him know you are not ignoring him. You understand he has something to say or ask, but IF he will wait a moment, you will listen to him.
We taught our daughter to quietly stand next to me, lightly touch my hand and say, excuse me.. Or pardon me. I told her I would look at her to let her know i heard her, but I was not going to be ready to listen to her until I spoke to her.
Also in these situations we always said," thank you for being patient, what did you need to say?"
We also taught her to say, "this is an emergency.." But only if it was a real emergency.. Like someone had gotten hurt.. etc. Again a positive, thank you for letting up us know..
The other thing we did tell her, is that if she rudley interuppted, the answer would be no..
Funny story.. When our daughter was 4, I was at work and my husband was working on his car. Our daughter was outside playing like she was working on her car..
My husband said our daughter kept saying.. "excuse me dad".. Or "pardon me dad".. He kept saying, j"ust a minute".. and then "just another minute".. even though these were LONG minutess..
Finally our daughter said very calmly.. "Dad, this is an emergency.."
He said "well what is it?".. She said, "Scotts house is on fire"..
Yep, the neighbors house had flames coming out from under their house that were flaming up the side of the house.. Fire dept was called.. The neighbor had been using a heat gun to scrape the paint off of his house all summer.. while we were in the drought.. Idiot.. We had warned him..
But our daughter used her words.. and used her manners.. My husband started paying more attention to our daughter when she needed his attention. after that.
This is pretty normal for this age and so you do need to state the rules and expectations. Mopdel the behaviors as a family and reinforce with positive when he follows the behavior and disappointed when he does not.