Why would he flip, last ditch get the FBI off my back or else?
I don't believe Trump could resist the urge of a sex party of whatever sort, wandering hands, the way he talks about woman he wants. His pants would be off before you press record. The problem is, a sex tape is always leverage even post Presidency so it's not something you would likely unveil to everyone.
Sater has worked as an FBI informant previously.