When Cruise and Kidman roled opposite of each other in EYES WIDE SHUT - after the movie hit the box office they already had split up. Their characters were too similar to themselves in real life. It was to close for comfort.

It was like they were acting out their own life and that scared them to death. Kidman learned to stand up for herself and be strong - that broke their union.

"I think EYES WIDE SHUT was the process that brought it to anend because the characters they played were so close to themselves."
Reported BreakingNews.
Source: breakingnews