Charlie Sheen has bought his girlfriend a new Mercedes Benz car.

The 'Anger Management' actor treated porn star Brett Rossi - who he has been dating for around a month - to the expensive vehicle earlier this month to show he is serious about her.

A source told ''Charlie always buys his girlfriends new cars when they begin dating, or gives them access to one of the vehicles in his fleet. Two weeks ago, Charlie bought Brett the Mercedes.''

However, Charlie has registered the car in his own name not Brett's.

The source added: ''It's not in Brett's name, though. It's in Charlie's. He never puts the cars in his girlfriend's name!''

The motivation for the 48-year-old star having the vehicle in his name is that he gets his purchase back if the relationship doesn't work out.

Brett - the star of such adult movies as 'My Sister's Husband', 'Kiss and Tell' and 'Fantasy Girls' - has also been given a credit card by Charlie to spend on herself and the romantic actor is taking her to Europe for the Christmas holidays.

The source revealed: ''Brett is so excited to be spending Christmas with Charlie in Europe and is loving the lifestyle of private jets, fancy dinners and designer clothes.''

Charlie booked the festive break after learning he won't be able to see his daughters Sam, nine, and eight-year-old Lola - his children with ex-wife Denise Richards - or his five-year-old twin sons Bob and Max with third wife Brooke Mueller over Christmas.