Obviously you telling him isn't working. What he's heard only makes him mad/defensive, probably because he knows in his gut there is some truth to it. So, telling him again is only going to make things worse, not better.
Maybe you should focus on the thing they do together and comment on how much D8 enjoys it? Really play it up, make a big very positive deal about it?
Michelle - Proud DR Rockette S: 28JUL07, D'd: 29OCT09 http://tinyurl.com/27j9qo2