The 46-year-old rocker was seen getting close to the lingerie model - who is 12 years younger than him - while they were both at a bar in West Hollywood recently.
And the blonde Canadian bears a striking resemblance to a younger Kate Moss, sporting sharp cheek bone and long beachy hair.
Jessica revealed on Instagram that she had been backstage at Jamie’s band The Kills’ concert in Hollywood - seemingly going onto a bar with the guitarist after the show.
A source on the scene told The Sun the pair were ‘very flirty with each other, very cuddly,’ adding that: ‘Kate will be devastated to see Jamie moving on with a younger version of herself.’
Despite neither Jamie nor Kate admitting that they have split, the couple have not been pictured together in months - with insiders attesting to them having serious relationship issues at present.
However, both Kate and Jamie were spotted wearing their wedding bands this week while in London and LA respectively, proving that perhaps this couple are not quite ready to give up on their marriage just yet.