Det här låter som det exakta plotet av Derailed från 2005 med Clive Owen och Jennifer Aniston.
On a commuter train, Charles [Owen] encounters an alluring woman named Lucinda Harris [Aniston]. She is a married financial adviser. [...] Ultimately, they decide to consummate their affair and wind up in a seedy hotel. An armed man — later identified as Philippe LaRoche (Vincent Cassel) - bursts into the hotel room, beats Charles, and brutally rapes Lucinda. Charles and Lucinda agree not to report the crime, as they do not want their spouses to learn of the affair. Shortly after, Charles is blackmailed by LaRoche, who threatens to kill his family if he does not pay $20,000, which Charles promptly pays. A month later, the attacker calls again, this time demanding $100,000.
Det visar sig vara en bluff som "Lucinda" (riktigt namn Jane) är in på. Här är trailern: