Parental Sneakiness

A man in Brisbane calls his son in Adelaide (2000 miles away) two days before Christmas and says, "I hate to ruin your day, but I have to tell you that your mother and I are divorcing; forty-five years of misery is enough."
 
"Gees Dad, what are you talking about?" the son screams.
 
"We can't stand the sight of each other any longer," the father says, "we're sick of each other, and I'm sick of talking about this, so you call your sister in Darwin (1500 miles away) and tell her."
 
Frantic, the son calls his sister, who explodes on the phone. "No way they're getting divorced!" she shouts, "I'll take care of this."
 
She calls Brisbane immediately and screams at her father, "You are not getting divorced. Don't do a single thing until I get there. I'm calling my brother back, and we'll both be there by tomorrow. Until then, don't do a thing. DO YOU HEAR ME?" and hangs up.
 
The old man hangs up his phone and turns to his wife. "Okay," he says, "they're coming for Christmas and paying their own way."