Mumbai: So, is it over? Did Ranbir and Katrina finally break up last week? These questions have been doing the rounds lately in the tinsel town of Bollywood. But, if you are finding this piece of news as juicy then wait till your senses are pampered with a juicier piece of news, the reason behind the alleged break up.

According to a source, Ranbir’s bonding with Nargis Fakhri, a Kingfisher calendar girl may be the reason.

It is true that the couple's relationship had a rocky run from the very beginning. Their arguments constantly revolved around insecurity and loyalty issues. Kat felt RK wasn't giving her enough time, while he felt extremely stifled towards the end. After her split from Salman, Kat wanted to give her relation with Ranbir everything. There was even a time when she contemplated going public about their pyaar.

But then, things took turn for the worse. With the entry of his Rockstar co-star Nargis Fakhri, a Kingfisher calendar girl, who along with her looks had the right attitude to attract RK's attention. A source spills the beans on how things went down, "It wasn't a surprise for anyone.

They had been arguing and fighting for over a month. When the new gal got in the frame, it only got worse. Kat was totally against him spending time with her. There were times when he was with Fakhri and wouldn't pick up Katrina's calls. He said they were meeting to see the film's rushes, but later she realised he was just making excuses to spend time with her."

What seemed like mere infatuation at the start, turned serious when Nargis got a chance to visit the Kapoor household in Delhi. The source adds, "When Ranbir took her to his sister Riddhima's place it was a big step. It upset Kat that he was introducing her to his family when they were still going around. She felt like he was two-timing her with Nargis."

DEEPIKA FACTOR: It is believed that Ranbir's ex-girlfriend Deepika Padukone's interest in acting with him was also a bone of contention for Kat. She was extremely upset with the news that Deepika might be doing Ayan Mukherji's next with RK.
"Even though RK and Deepika have got over each other, Kat wasn't pleased with the idea that they would be working together in the same film. She even expressed her apprehensions to Ayan who told her he hadn't finalised anyone yet."

IS IT FINAL? Close friends are of the opinion that Ranbir-Kat are done for good. Ranbir is clearly besotted by Fakhri and has been raving about her to all his friends. When asked if their love story was scripted to benefit their film, the source quipped, "Not at all. They are truly in love. Spend time with them and you would know."