Cat-on-the-roofing

"If you think there's a chance you might hve to cancel on Michael for Friday night," she said, "you'd better cat-on-the-roof him now".
I was understandably perplexed by this. "Cat on the whatta?"
Cat on the roof," my mother said. "you meed to begin mentally preparing him for the disapointment. For instance, if i said something had happened to Fat Louie while you were in Genovia - " my mouth must have afallen open, since nothing mum said "don't worry, nothing did. But im just saiyng if something had, i would not have blurted it right out to you, over the phone, i'd have prepared you gently for the eventual let down. like i might have said "mia , fat louie escaped through your window and now he's up on the roof, and we can't get him down"."
"of course you could get him down...blah blah"
"Yes"..."but supposing I told you i'd try that. and the next day i called youy and said it hadn't worked, and had escaped to the neighboru's roof"
blah blah blah
"So you'd be mentally prepared when I called you on the third day to say despite everything we'd done, Louie was dead".
..
...
"I'm saying you should begin mentally preparing Michael for the disappointment he is going to fell if, indeed, you need to cancel him on Friday night. Call him and tel him you might not be able to make it. That's all. Cat-on-the-roof him".