Another woman may have indeed been the real cause behind Cara Delevingne and Michelle Rodriguez pulling the plug on their relationship, and the reported culprit is none other than another famous face the model has previously locked lips with.

Sienna Miller is Cara Delevingne's 'Schnoyster?'

Actress Sienna Miller reportedly came between the 21-year-old model and her 35-year-old girlfriend at the time by inserting herself into the relationship after becoming obsessed with Delevingne sources now say.

"When Cara was dating U.S. actress Michelle Rodriguez, Sienna was always getting involved and it caused an issue," sources told The Daily Mail June 15. "She was always kissing Cara, which Michelle wasn't keen on."

Cara Delevingne 'Needed A Break' From Michelle Rodriguez?

Now that she has reportedly successfully broken up the pair, the actress now has sources concerned for Delevingne's other close friends, as it is feared she will successfully get them, including BFF Suki Waterhouse, out of the model's life as well.

"Sienna is relentless about wanting to spend time with Cara. She seems a bit obsessed," the source added.

Rumors first started flying that there could be something more between the model and actress after they were spotted leaving LouLou's Club in Mayfair, London April 29 together, and strolling hand-in-hand. Delevingne did nothing to combat the rumors when she was spotted arriving in New York just days later for this year's Met Ball, telling reporters who ran into her at JFK that Miller was her 'Shnoyster.'

Though Miller is currently engaged to actor Tom Sturridge, and the couple has a daughter together, Marlow Ottoline Layng Sturridge, she has had a rather tumultuous romantic history in the past.

She and actor Jude Law split in 2006 after he admitted to an affair with the nanny of his children, and she was rumored to have romanced actor Daniel Craig. She was also involved in a widely publicized affair with married actor Balthazar Getty in 2008. She and Law reportedly rekindled their relationship again, before calling it quits for good in 2011.