Is this normal or not?

My 12 year old son has a friend who is also 12.  This friend never talks, cannot play in a cooperative group setting, always looks at the ground and has very little facial expression.  We have known this boy since he was born and when my son turned 5, we moved off the block where this other boy lived.  Watching this boy as a baby, he always developed late.  He didn't crawl until he was 14 months and always looked like he was in space.  He never talked much and cried a lot as an infant.. We didn't see him until again until they 5th grade where they now attend the same school.  We have had this boy over lots and he just wants to play video games and that's it.  He doesn't like sports, which is fine, but I always like my son playing outside rather than glued to a video game.  This boy is overweight and never exercises. He has trouble getting his hmwk turned in and doesn't like school.  He doesn't do well in large group settings where there's lots of cooperative play going on and basically looks very uncomfortable.  
I'm concerned that he has some social issues and while he's at school, he tags along my son and the teachers are saying that my son needs to break away from him.  If the other kids are playing football at school, my son will hang back with this other boy and not participate.  
His parents are doing nothing about it and have never done anything about it.  Never any play therapy as a toddler and as far as I know, and they still don't think there's anything wrong.  Do you see this behavior in a 12 year old boy normal?
My 12 year old follows me around talking all the time, loves playing football, bb and other sports with his other friends and is a very happy child.
I'm torn about how to handle this friend, b/c I have known the parents for 12 years.  But at the same time, I am worried for the friendship between the two.I want my child to have lots of friends, but this one friend is constantly wanting to be with my son.  
What are your thoughts????  

[Rachel Thompson, Ph.D., BCBA]

It sounds as though your primary concern relates to your son and his relationship with the boy you describe. This seems like the best focus, given that your son's friend's parents, teachers, and pediatrician are apparently not concerned about his development. Here are a few thoughts:

(1) To me, it is great that your son has a variety of interests and the ability to get along with lots of different kids.
(2) I would not be concerned about your son playing video games and playing inside sometimes, as long as he also has other interests. He sounds like a well-balanced kid. If you see that he is beginning to spend too much time on any one activity, you might considering expanding his experiences by providing him with other opportunities (e.g., inviting some different friends over, signing up for a sport).
(3) If your son spends a great deal of time with this child, he must enjoy his company. It may be helpful to talk to your son about what he likes about spending time with this child.
(4) You could consider encouraging the two children to do some different activities when they are together. Perhaps your son could give you some ideas.

[Natta1980]

I am not an expert, but......
I would certainly be worried about only one thing - teachers that are saying that your son is trying to break away from him.

Your son made a choice to be this boy's friend - probably he sees that he is left behind....

Unless you see any regression in your son - let them be friends.

Provide some interaction opportunities - other than video games - offer them activities. Try to play sports with them.

I always made friends with unpopular children - I felt bad about them being bullied by "popular children"........I helped them to study and socialize, as I was fairly popular and straight "A" student, but the person who got the most of these relationships is me.

Try to talk to your son for starters - it maybe that he is introverted by nature and does not mix well with all the jocks.