Thank you both. Actually, he seems to be going through something a bit bigger than I thought.
Last night, he cried about the loss of a friendship with a boy he hasn't really seen at all this year. It's no great loss to us, since we don't think this kid was that interested in a friendship with DS anyway (plus he's quite rude), but DS doesn't recognize this and is rather broken-hearted. I tried to explain that it's normal that things change and that friendships come and go, and I also pointed out that he wouldn't have a friendship with his new best buddy if things didn't change. Not sure it worked that well, but maybe some of it sank in.
He is also very attached to "stuff" generally and doesn't want us to throw anything out. He is embarrassed to let anyone else hear him when he tells us this, but he wants to keep everything as a souvenir. He cried when I suggested I would throw out an old broken hockey stick.
He's such a sensitive kid and mostly that's a wonderful thing. But I do wish he didn't get hurt by everything so much, plus I hate to see him so insecure. And just when I thought he was doing so much better... Sigh.
