Obviously a flaming type of title, but:
I bring up my dcs to be kind, share, be great hosts, polite, etc.... However whenever they go elsewhere (and I've seen it in my own home) the other children do not have to share and as long as they're out of the way noone bothers to check that they're sharing, not playing on inappropriate games on the internet etc.
I am torn between making them as egocentric as the other children or keeping them kind and therefore walked over. I have said to DH that I'm not going to force them to play whatever their friends want when they come here anymore.
This egocentric precious Johnnie syndrome even stretches to parties where children have some to a party and then 'chosen' children for something extra like a sleepover....