I have come to learn that when I coach the people who report to me, it is always better to address a situation head on. Ask if they would be open to receiving some feedback (or in your case, if they would be willing to let you open up). Be polite and ensure they know there is nothing personal here so they should not take offense. Open up honestly, but you don't need to be apologetic for making the right choice for you. That said, remember to empathize, regardless of their reaction.
Or just have a friend pass the guy a note during recess. That always seemed to work in grade school.