...because I can't tell whether mine is completely normal or not.
He is constantly worrying about who is friends with who, and when he has friends over to play, he doesn't make them welcome, treat them particularly kindly, share toys etc.
They seem to have riotous fun one minute, and the next they have fallen out... so a friend to play is a tempestuous 3 hours.
I honestly can't tell whether he is lacking in social skills, or whether other boys can also be this way. When we talk afterwards, he says he's had a nice time and is keen for the friend to come back soon.
Any thoughts appreciated.