Watch: Arnold Schwarzenegger's Son Joseph Baena Celebrates First Bodybuilding Competition WinArnold Schwarzenegger's relationship with his longtime girlfriend Heather Milligan is anything but expendable. After all, the Terminator alum and the physical therapist recently enjoyed an intimate date night, grabbing dinner together at Japanese restaurant Nobu Malibu. For the low-key affair, Arnold, 78, donned a gray sports jacket over a black sweater and blue jeans. Meanwhile, Heather, 51, wore a white blazer with gold buttons paired with a white top and black bottoms.