Rafael got better about sharing after going to pre-kindergarten, but we were, for a while, worried that Markus would be a pushover and Rafael would run roughshod over him.
It hasn't turned out that way, which is good, kind of. But now Markus is all about, "Rafael's not giving me MY turn," and isn't good about sharing with Rafael. In fact, he's horrible about sharing with Rafael.
So how do you deal with sharing issues?