DS is a collector. He'll organise, stack, line-up and arrange cups at the table in my parents house and have a great time.
But my niece who is the same age will wander up and want to join in the fun even though it isn't actually fun for her in itself, she's just wanting to socialise and interact. So we try to give her a few of the cups. Cue enraged DS and my sister making snidey remarks about my bad parenting / pandering to him etc
At the craft table DS wants access to all the feathers or all the beads or pens or whatever when there are others who actually want to create things.
And the inevitable battle with regard to the "longest line of magnetic trains" despite the autistic child next to him having the exact same plan.
"Sharing" is in DS' IEP / targets but I can't see how it will happen. We don't force NT children to "collect" so is it even appropriate?