Kanye West has reportedly been having regular conversations with his ex-girlfriend Amber Rose.
Since the pair split in 2010, both have gone on to start families with new partners. Amber, 30, married rapper Wiz Khalifa in 2013, and they have 11-month-old son Sebastian together.
Kanye and his fiancée Kim Kardashian are expected to wed later this year, and have baby daughter North, who is seven months old.
"It's shocking because Kanye is so paranoid about Kim's exes. Before she became pregnant he asked her to cut contact with them all," a source revealed to British magazine Now.
"He's even talked about getting it written into their prenup that she won't talk to any of them. So for him to be talking to Amber, of all people, is playing with fire."
In 2012 Amber claimed that 36-year-old Kanye had begun a secret affair with Kim, which led to their split.
She labelled the reality TV star a "home wrecker", claiming she had been sending Kanye pictures of herself, in an interview with Star magazine.
Kim was dating NFL star Reggie Bush at the time.
"Kim and Amber have a lot of bad blood between them. It's incredibly disrespectful of Kanye to be talking to her behind Kim's back.
"In reality, Kim doesn't have anything to worry about. Amber's totally devoted to Wiz, but it's still really inappropriate - especially considering Kanye's determined she doesn't talk to her exes," the source added.