How Could I Have Missed it?

I just realized yesterday there is a mistake on my Swingers poster -- I've had it for 5 years. It says:
"Baby, we're gonna give big daddy the old Rainman sweep. Can you dig that money? Vegas baby, Vegas!"

It should read: "They're gonna give daddy the Rain Man suite! You dig that? We're going to Vegas, Mike. VEGAS!"

I don't even know what "the old Rainman sweep" even means.