The outspoken British comedian has been nursing the Firework singer through her painful break-up with John Mayer -- and sparks are flying between the former couple, RadarOnline.com is exclusively reporting.
The pair still talk, despite their sudden shock divorce and Katy, 28, has been texting Russell, 37, for advice.
“Russell may appear like a comic book character, but he’s got a wise head on his skinny shoulders,” a source tells Radar.
“Katy reached out to him after she split with John, bemoaning her luck with men and Russell provided her with some much-needed reassurance.
“He flattered her with compliments and just listened to her every word. Russell also used his wit to cheer Katy up.
“They were the best of friends when they were together, and despite the fact they are no longer married they've managed to stay civil to one another.
“She’s very respectful of Russell’s reasons for their break-up and would never overstep the line by begging for him to come back.
“But she does, however, think that he was definitely the love of her life. It’s left a lot of people wondering if she thinks that she could have fought harder to save their marriage,” the source reveals.
As RadarOnline.com previously reported, Mayer, 35, wasn’t happy that his now ex-girlfriend was still on friendly terms with Russell.
The lusty Lothario grew tired of Katy’s comparisons between him and Brand, and it created a tension between them that threatened to boil over at any point.
“John and Katy together were like a volcano just about to go off,” a source revealed.
“Their relationship was incredibly volatile, stemming from the jealousy they both harbored deep inside.
“Sure, Katy was unhappy that John constantly flirted with other girls and played up his heartbreaker image, even when she was standing next to him.
“But, Katy gave it back. She knew that she could push John’s buttons by comparing his flaws to what she saw was great in Russell, which he hated!
“Katy and Russell still talk to one another, and that was another thing that irked John. He’s never been in a relationship where he wasn’t the main focus all the time and it bothered him,” the source said.