Rosie's BFF Millie Manderson (nee Mackintosh), who is married to Pro Green, reportedly introduced the pair to each other at the end of the summer.
According to sources, Millie and Rosie even flew over to Paris to watch the former Rascals and Last Shadow Puppets star perform at a gig.
An insider told Mail Online: 'Millie introduced them three months ago and they got on like a house on fire."
The Chelsea girls have been best mates for years, however they fell out in 2011 when Rosie apparently slept with Millie's love interest and fellow MIC star Hugo Taylor - which Rosie denies.
All is rosy (excuse the pun) between them now though and Millie and Rosie are said to be enjoying double dating with their men.
In September, Rosie joined Millie and Professor Green on their wedding day in Somerset.
More recently, they were both pictured having a catch-up at Professor Green's birthday party in London.
Rosie hasn't mentioned the relationship rumours on Twitter. Reveal has contacted Rosie's rep about the reports.
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