Seconding this. He sounds smart enough to understand "Hey, I need a few minutes, but I still want to talk".

Raising our kids, we never used reasons like "because I said so", we always explained why we made the decisions we did, so our children learned reasoning and understanding as they grew. Kids are generally quick to learn, and can understand most situations if explained plainly. Talk to them with clarity and respect and you'll be surprised at the response you get.