It seems like insiders are alleging that Robert Pattinson knew all about Kristen Stewart's and Rupert Sanders affair seeing as the pair has a pretty open relationship.

A new report is claiming that the "Twilight" costars had the type of relationship that was based on a "100 percent honesty policy" and they'd both shared previous infidelities with each other.

According to RadarOnline.com, a source revealed that the famous couple had few secrets between the two of them.

The insider explained, "When they were officially dating, they always had a policy of 100 percent honesty, which did create issues. Robert was always very frank about his flings with other women and that worked for Kristen too."

The pal of the couple continued, "They had an open relationship and it's amazing that Kristen hasn't revealed this info when she was being painted as a 'jezebel'. Rob has had other women on the side and Kristen has had other women and men as well."

The source revealed that the famous couple took a "bizarre approach to relationships" and it was more business than romance.

The friend admitted, "Their relationship was always a business and a spiritual partnership more than a romantic one. Rob and Kristen often said they might never see each other again after the last Twilight press tour and that's pretty much what happened, except for their 'are you in town' booty calls."

The insider confessed that Stewart and Pattinson didn't see a point in lying to each other. The friend said, "They were pretty up-front with each other when they got sick and tired of each other. It was the strangest relationship, but keeping each other at arm's length is working in their favor."

Following their split and her cheating scandal, the pair continued to keep in touch with one another. The insider revealed, "Kristen and Rob are still close and definitely in contact," adding, "and they still sleep together when the opportunity comes up."

Do you think Kristen Stewart and Robert Pattinson had an unusual relationship or is that a romance you would like to have with your boyfriend/girlfriend? Let us know in the comment section below.