Following his break up from Kristen Stewart, Robert Pattinson has allegedly began dating Riley Keough, his ex's friend and former co-star. Although Stewart was said to feel betrayed by the two she seemingly kept quiet about the situation up until now.

According to Entertainment Wise, the "On the Road" star called up her ex's new girl. The star was unhappy about the rumors that Keough, who she considered a friend after forming a bond on the set of their film "The Runaways" would betray her in such a way.

An insider revealed that Stewart, "called Riley. She likes and respect her, but she just doesn't feel like it is ever right to go after a good friend's ex who is suddenly on the market."

The source added that Stewart thinks the hookup between the two is "really uncool," but she did not go off on Keough, she remained calm during the conversation and there was no argument between to the two.

"It was a civil conversation where the takeaway was that Riley was sorry that Kristen felt that way", the source said.

According to Hollywood Life, Keough is conflicted, a friend said, "Riley doesn't want anyone to make her choose between Rob and Kristen."

A source told the site that "[Rob and Riley] are still seeing each other, however, it's mostly physical. Rob was a little scared off that this new relationship was going to be a media firestorm, so he has slowed things down, so mostly it's a physical relationship.

"They don't consider it dating, but everyone around them does."

Do you think Kristen was wrong for confronting Riley Keough for dating Robert Pattinson? Leave us a comment below.