Hi!
Do you stay well back when it comes to friendships? Do you say anything if it's obvious something is bothering regarding friends? Just make them aware you know and that they can come and talk to you?
DS has just turned 13, year 8. I imagine him to be a likeable lad, quite cool, very kind to friends ( I fear a walk over but don't know how to deal with that!) but he always seems to get left out of stuff 
. Think it's getting him down.
I don't want to encourage him to arrange stuff himself because I actually think that makes it look worse as he's made the effort to sort stuff with friends and it's not reciprocated. I'm talking him arranging to do something with say 4 friends and then finding out next time that those 4 friends have gone out and not included him.
He's quiet when it comes to a lot of things, moody, but you can tell when something's bothering him.
Do I say anything to him? Or leave him to think about it himself?
I actually don't know what I would suggest!