The 25-year-old star was spotted rowing with Thomas Cohen on a train into central London over the amount of songs she had on her phone by the American singer, who committed suicide 10 years ago, according to the Sunday Mirror newspaper.
Passengers onboard the train at the time claimed Peaches turned to her husband and said: ''Look, I can't believe all my songs on here are Elliott's.''
The S.C.U.M rocker then snapped back: ''For f***s sake, what is your obsession with that man!''
The blonde beauty replied with: ''Look, I'm married to you. Stop getting so jealous. We've got two kids together for f***'s sake. What more of a commitment do you think there can be. Don't be so jealous.''
The couple, who have sons Astala, two, and Phaedra, one, together, then sat in silence for 10 minutes before Thomas, 23, got off the train at London Bridge, while Peaches continued her journey to Charing Cross.
A passenger told the paper: ''It looked like the sort of row any married couple would have, neither acted that badly.''
However, just four days after their bust-up, Thomas found Peaches' dead body ''slumped'' over the bed at their home in Wrotham, Kent, England on April 7.
An inquest heard last week that heroin ''likely'' played a role in her death after the highly addictive drug was found in her system following a recent toxicology test.