S.K.
Your son is old enough to remember his actions for a day or longer. So the best thing to do is make a time and schedule to take him to various places he likes when it is just you and him. It could be to a park or fountain or swimming pool, micky d's to play in the tunnels etc. When you are going to be around other people, you need to give him plenty of warning. Tell him that you and he are going to be going to one of these outings and exactly when. But then also tell him that if he doesn't allow you to have a conversation without him acting up, interupting, and generally being naughty, then you will not go to this place. You HAVE to be ready to follow through for this to work. This may take a few times to make it work. If you really want to make it work, you need to set up a scenario where you will be with an adult the day of or the day before EVERY outing. If he doesn't get his outings for a month, so be it. This works for me and my daycare children. I believe it's very rude when children behave this way. It's also very rude when parents allow them to get away with it. The person on the other end of the phone or that conversation in person is probably rather tired of being interupted.