Hero worship problem | ADHD Information

My son, (12 yrs, ADHD) who is a great kid most of the time, just LOSES IT when his 12 yr old cousin comes over to play. He adores his cousin who he just about grew up with.  As time has moved on, they now both go to different high schools and made different friends so don't see each other as much.  Whilst this does not worry the cousin, who is an extremely popular boy, my son misses him terribly.  If he knows he is coming over for a visit, he will go and stand beside the road waiting for his cousin to show up. 

He will drape his arm over his cousins shoulder, hug him, hang on every word his says, and so on.  I can see his cousin just barely puts up with it and doesn't really like it. The cousin will also drop my son like a hotcake if someone else is around. It really pains me to see my son behaving this way and I try to talk to him and explain that he needs to be his own person and not be so needy with his cousin.  He understands but of course, it all happens again next time they see each other.  How can I get him to see how he is behaving?

They used to spend a lot of time together until my sister began a new relationship.  this guy has two boys near the cousins age so he has 2 new friends living half of a week with them.  My son doesn't see as much of him and I guess this has made the hero worship even more intense. 

I agree that I should do some role-playing with him and see if he 'gets'I it.  He does have trouble reading social cues and maybe that will help.  I asked him last night if his cousin asked him to do just about anything in the world would he do it....his response was 'just about anything'.  I thought that was a bit scary considering teenage years are just down the road and my immediate thought went to drugs.

That does sound heart-breaking.
Do the cousin's parents know what is going on? Maybe they could talk to him too so that he shows a little more sensitivity to your son's feelings. He may be Mr. Popular now, but one day he may need and appreciate his loyal cousin.
Have you explained to your son that friendships grow and change over time and sometimes cool off? It doesn't mean that there's anything wrong with him or that his cousin doesn't like him, just that his cousin is into other things right now.
Have you tried telling your son very specifically what behaviors are off-putting to the other boy? It sounds like he is having trouble reading social cues and just backing off a little (keeping his hands to himself) might make a big difference. Maybe try role-playing with him?
That's all I can think of other than, does your son have anything that really interests him? I would really encourage and build on any interests your son has so that he has something he really feels good about (and maybe some friends who share the same interest).
Kids are resilient and unfortunately sometimes losing friends is part of life. Of course a cousin will probably have to stick around one way or another. It could be that they will be close again a few years down the road. You never know!
Good luck!

I wonder if they spent more time together on a more regular basis if the novelty would ware down a bit.

I don't think that it needs to be a formal 'visit' sorta thing, perhaps just running into eachother at the market/mall/etc and things like that...