Sienna Miller only agreed to holiday with Jude Law and his children in the Caribbean over New Year if he left their nanny at home.
The 'GI Joe: Rise of the Cobra' actress joined the actor - whom she broke off her engagement to in 2005, after she found he had cheated on her with his children's carer Daisy Wright - in the Caribbean, but only after he agreed to her ultimatum.
A source told the Daily Mirror newspaper: "Haunted by what happened the last time they were together, Sienna is leaving nothing to chance second time around.
"She wants her and Jude to work on their friendship first and foremost, and then see if love blossoms.
"But by the same token, she doesn't want any reminders of his infidelity.
"So she's made sure the children's nanny has returned to England before she joins Jude on holiday in Bequia, from Barbados.
"Sienna wants it to be just her and the family, and for them to have a quiet, low-key celebration together."
Jude is spending the festive period with his three children - Rafferty, 13, Iris, nine, and Rudy, seven - from his marriage to actress Sadie Frost as well as Sienna, which has reportedly upset his parents, as they don't approve of him reconciling his romance with the 'Edge of Love' star.
Another source said: "They have made it abundantly clear he doesn't have their blessing. They want him to be happy but think the two of them together is a recipe for disaster.
"They believe the relationship was a rollercoaster the last time and they were left to pick up the pieces when it finished."