Bi Kristen Stewart & Robert Pattinson Had An Open Relationship!

Brace yourselves, Twihards: Twilight stars Kristen Stewart and Robert Pattinson have some big ol' bombshells!

Kristen Stewart was revealed by a Radar Online source as being bisexual -- and in an open relationship with Robert Pattinson, which reportedly worked for them beautifully.

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

The source added, "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."

What's more, the couple knew they wouldn't exactly go the distance, and that was fine by them, too. The R-Pattz and K-Stew pal continued, "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. 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.”

That's in present tense for a reason: "Kristen and Rob are still close and definitely in contact, and they still sleep together when the opportunity comes up."

So everyone slut-shaming Stewart for cheating with Rupert Sanders and sobbing for Pattinson? Ease up!