Who would have thought that the real-life 50 Shades of Grey-style BDSM relationship between a 53-year-old Ivy-league graduate investment banker and his 27-year-old live-in slave would have ended in 40 text messages, a "knock-down, drag-out fight" and an arrest? And yet, the New York Post writes today, that's exactly what happened.

The submissive [Frankie] Santiago exploded in a fit of rage, law-enforcement sources said, allegedy shattering Sonderling's car windshield and bombarding him with dozens of text threats. [...]

Santiago - who is known in the bondage-domination S&M community as Althea Lyn - was arrested Monday after what sources said was a knock-down, drag-out fight with [Edward] Sonderling at the East 57th Street apartment where she once did his daily bidding.

She was arraigned yesterday on charges of stalking, criminal mischief and aggravated harassment.

Santiago had been Sonderling's "slave" for three years ("Basically, she was there to serve his sexual needs," a source told the Post "She's his toy, his fetish slave."), until she discovered he'd been seeing someone else. Relationships are hard, even for investment bankers-turned-S&M masters! Sonderling, a Brown and Horace Mann graduate and CEO of his own investment firm, Priority Investors LLC, refused to comment, and Santiago didn't respond to reporters.

Apparently, "Scads of photos posted on social media sites show the two - clad in leather, latex rubber and bondage gear - hamming it up and grinning for the cameras," but we were only able to find the above photo of whips made for "King Eddo" by "Saint Leather." So if you, uh, see any, put them in the comments.