Speaking in an interview with ELLE, Katy said she sent Kristen a message saying:
I’m just trying to be a friend to him but it is unfortunate that I do have a set of t*ts
“I know you’ve seen all this stuff but you know I would never disrespect you. I’m not that person,
“I’m just trying to be a friend to him but it is unfortunate that I do have a set of t*ts.”
Reports at the time claimed Kristen felt 'betrayed' when Katy was spotted with her ex on several occasions since the Twilight couple split in May.
But a US celebrity news site has claimed the Fireworks singer has always been closer to Rob.
Their source told said: ‘Katy has been really supportive of Rob since he and Kristen split up. She has been his main support during this whole breakup. Kristen has tons of friends that she can lean on, whereas most of Rob’s closest friends are in England.
‘Rob and Katy have always been better friends and [Kristen] doesn’t think there is any type of romance going on between them.’
Meanwhile Katy has reconciled her relationship with singer/songwriter John Mayer following their split in February.
I'm not interested in taming anyone - I'm pretty wild myself
She told ELLE: 'He pulled away. That was a big hello for me.
'I realised I could lose the person I loved and I had to deal with some things, issues I think a lot of women have.
'You can be strong in one aspect of your life but submissive in another.'
Having also gone through a divorce with Russell Brand last year, Katy confessed she was attracted to 'challenging' men.
But added: 'I'm not interested in taming anyone - I'm pretty wild myself.'
My days of celebrity saving are over
It seems this outlook extends to Katy’s girlfriends as well, as she opened up about her friendship with fellow ‘wild’ popstar Rihanna.
She said: 'I love her and every time I see her, I'm reminded of the light that she has.
'There's a lot of dark in this business. I know a lot of people out there with the most detrimental entourages - they are the root of their demise. It's really unfortunate but
you can't save these people. My days of celebrity saving are over!'