Thanks for the tip. Unfortunately I can't it streaming anywhere. I found a music video for the scene which shows her ass getting fingered, but it's very short.
I found a download here: http://rapidgator.net/file/ee990c5c037a75cd3d3030287c383f0b/AssParade.Gianna.Michaels.Bobbi.Starr.Lorelei.Lee.Las.VegASS.BABY.mp4.html