This behavior is entirely normal and has nothing to do with sexuality. The use of the tern 'attraction' implies some sort of sexual interest, and this is not relevant. You can be assured your son is acting in precisely the way that would be expected of a child his age.
I'm no doctor but I'm a man and was once a boy. Sounds like your boy is just being a boy...nothing to worry about. Especially at that age, boys like to play with other boys...the hugging thing shouldn't be of concern until he gets older, like 8-10 and up.
I agree with the playing, but I just find that the way my son put his arm around the little boy at McDonald's and how he is very affectionate with his cousin is strange, but I am sure it's normal. I guess I am just very observant and tend to worry too much and over analyze. Thank you for your comment.
Your son is a normal boy. The reason that he is excited about playing with a boy cousin or otherwise, is because he has a sister and does not get to play with boys as much. Boys like to play with boys. By the time boys get to first and second grade, most boys play with boys. If you go to a both sex type school during recess, you will notice that boys are playing with boys and most girls play with girls. That is total normal behavior. I actually would worry if all he wanted to play was with girls. His behavior is very normal. Enjoy him.
Thank you for your replies. I know all children are different, but I was concerned about his behaviour. I am a very "hands on" mom, who tries to pays a lot of attention to their children - maybe too much. I also tend to worry a lot. If this is normal behaviour, then I need to relax. Thanks again.