ds1 obsessed with things being "mine"

[fattybum]

He's 6.2 it can be anything from his toys to the tree he's climbing in the park. It might sound like nothing but it's driving me mad. He'll say things like "can this broom/calculator/bottle be mine" if we say yes he'll go on about it "this brooms mine" and not let ds2 play with it.

Even on holiday recently he claimed a stray cat was his, then all the other children were calling it his cat. How can I teach him to be less possessive?

Have you discussed sharing - how even if something is yours it should still be shared etc? that makes the distinction between what happens when something is yours and when it isn't less defined - if the boundaries between his and not his are more blurred because even if they are his he still has to share them, he may lose interest in staking the claim?

Hmm, that's a good point. He's not bad at sharing toys with his friends, it's more his attitude that he has to own everything that bothers me, he just seems so selfish.