I’m sure this story isn’t as interesting as I find it, but this relationship has been intriguing me from the start. Back in 2006, Sin City director Robert Rodriguez met actress Rose McGowan while he was directing Grindhouse. Within a few months, Robert’s 16-year marriage to his wife and producing partner Elizabeth Avellan was over, and Robert and Rose were together. Robert later claimed that he and Elizabeth had been separated before he got together with Rose, but there was no legal paperwork filed, and I always found the timing a bit sketchy. Still, Robert and Elizabeth have five children together, and Elizabeth has remained Robert’s producing partner, so maybe their eventual 2008 divorce was totally amicable.

Since Rose and Robert got together – even getting engaged in 2007 – Robert has tried to make her into his muse and star of several projects that never quite got off the ground. There were rumors that no studio want to pay for any film with Rose in the starring role – and Robert’s inability to create a project for his lover is said to have caused considerable tension in their relationship. Now Radar is reporting that Rose has called off the engagement!

Rose McGowan has broken off her engagement to director Robert Rodriguez an inside source told RadarOnline.com exclusively.

McGowan recently filmed Rodriguez’s action-packed Machete- which co-stars Lindsay Lohan, Jessica Alba and Robert De Niro- in Austin, Texas and will next star in the she-devil comic book adaptation Red Sonja. Rodriguez is set to produce the film so maybe a reconciliation isn’t completely out of the cards?

Reps for the couple did not immediately respond for request to comment.

The couple officially announced their engagement in October 2007 after becoming romantically involved in 2006 on the set of the Planet Terror segment of Grindhouse, which was directed by Rodriguez and starred McGowan as a stripper with a machine-gun leg.

It was widely speculated at the time that their relationship was the reason Rodriguez divorced his wife of 16 years, producer Elizabeth Avellán. The director later issued a statement saying that he and Avellán had separated long before production began on the film.

McGowan, 36, and Rodriguez, 41, went public with their relationship in May 2007 when they arrived hand-in-hand at the Cannes Film Festival. They have been together ever since, despite false rumors that they had split up last year after financing for a Rodriguez-planned Barbarella remake starring McGowan fell through.

[From Radar]

Of course we don’t know what really happened. My guess is that it was about their careers more than their love. Robert was totally enamored with Rose – and he really did try his best to get studios to pony up major projects with Rose in the lead, like Barbarella, which was dead on arrival with Rose in the lead. There’s also Red Sonja, a film that Robert announced last year, but still hasn’t been made. Rose just took a supporting part in Robert’s Machete – and her billing is lower than Lindsay Lohan’s. Yeah, I would question an engagement if my director fiancée billed me lower than Lohan too.