Kristen Stewart and Robert Pattinson had a highly publicized break up after Stewart's "momentary indiscretion" with her "Snow White and the Huntsman" married director, Rupert Sanders.

Recently, reports indicate that the Twilight co-stars have given their romance another try. But trouble may be looming on the horizon again. Apparently, Stewart, 24, is reportedly mad at her friend, Katy Perry, 29, who allegedly, has been hooking up with Pattinson.

According to Celeb Dirty Laundry, "At one point, [Katy Perry] was good friends with both Rob and Kristen, but somehow, I don't see the same situation repeating itself here. She and Rob have clearly hooked up several times after his breakup with Kristen, and I don't see Kristen as the easygoing and forgiving type that will just forget that."

Perry and Pattinson are good friends, but sightings of the pair being cozy with each other have fanned relationship rumors.

In June, Perry and Pattinson were seen enjoying each other's company during the after-party of Pattinson's "The Rover" film. According to some RadarOnline sources, "When Rob saw Katy his eyes lit up. She looked gorgeous in a lace sequin black mini-dress, and they hugged and kissed." 

"He kept kissing her the entire night," continued the sources.

Could it be that during that time, Rob was playing the field? Maybe he was giving Stewart a taste of her own medicine?

While Stewart may be steaming, she's leaning on some of her other friends, whom she knows she can trust as a way to heal from her relationship problems.

HollywoodLife.com reports that the "On The Road" actress is planning on doing just that, hitting the road for an adventure.

An insider tells the site: "Kristen came with two friends, a guy and a girl and they all shared different lunch plates. She looked really happy and was smiling and laughing with her friends. They were all talking about taking a road trip and where would be the most fun places to visit. There was a Lonely Planet travel book on the table that they were looking at while they ate."

What're your thoughts? Are you rooting for Team Kristen or Team Katy?