I'm 15 and have no friends in school. Nothing I or anyone else tries ever makes much difference, and sadly the answer closest to the truth is that there isn't much you can do. The thing I would suggest and it would be cool if my parents did more is just to make the home environment more warm/friendly and comfortable, and maybe talk to him a lot about his interests or anything he wants to talk about really. Or, if he doesn't really want to talk, just let him work on his hobbies/interests and let him know he has a safe environment.
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Shy, awkward 16 year old communist girl whose main interests are 9/11, roller coasters and the 1917 Russian Revolution. I might not have any friends but somehow I have a really amazing boyfriend