|Dylan Penn and Robert Pattinson|
The 27-year-old actor is said to have moved on after a four-year on/off romance with his 'Twilight' co-star Kristen Stewart and is taking blonde beauty Dylan - who is actor Sean Penn's daughter - on a three-day luxury vacation next month.
A source told the Daily Star newspaper: "Rob wants to treat her to a break away. They have been seeing each other casually for months."
He is still said to be in touch with former love Kristen, 23, and was even reported to have been asking her for career advice recently.
Kristen - who Rob dumped in the summer after discovering she had been back in contact with her 'Snow White and the Huntsman' director Rupert Sanders, who she had a brief affair in 2012 - is said to be unhappy that the actor is taking Dylan on the getaway.
The source added: "Kristen is really upset that Rob has planned a romantic break with another woman.
"Rob still loves Kristen but he doesn't think it can work between them, he believes they both need a fresh start.
"He wants to jeep his options open, and he's looking forward to spending time with Dylan and getting to know her better in Hawaii."
Robert and Dylan were first seen in public together in September at the Chateau Marmont in West Hollywood and also attended a book launch party in Los Angeles last week.