Would it work to speak with your son, sharing that he can talk about his feelings with you and describing what you shared in your post?
There are also books such as
It's so much work to be your friend which may provide helpful insight and tips.
Have you seen these articles from the Davidson Database on friendships?
2005 Dr. Fred Frankel
http://www.davidsongifted.org/db/Articles_id_10352.aspx2006 Miraca Gross
http://www.davidsongifted.org/db/Articles_id_10400.aspx2007 Fr. Fred Frankel
http://www.davidsongifted.org/db/Articles_id_10484.aspx2010 Annette Sheely
http://www.davidsongifted.org/db/Articles_id_10628.aspx2011 Dr. Fred Frankel
http://www.davidsongifted.org/db/Articles_id_10686.aspx