owner

sama or san

The word "courtesy" means polite behavior that shows respect for other people.

Thus you would use a courtesy title when you were meeting people formally or introducing them to others.

Obviously, that depends on the appropriate courtesy title for his parents. http://en.wikipedia.org/wiki/Courtesy_titles_in_the_United_Kingdom#The_children_of_peers
If there is absolutely no nobility to be found, I guess "Sir" will do.

The title is purely a matter of courtesy or respect. It has no legal status.