Los Angeles: Brad Pitt reportedly proposed to Angelina on Christmas, but the couple chose to keep it under wraps until the press hullabaloo over Jolie`s directorial debut, `In the Land of Blood and Honey` had died down.
The couple confirmed their engagement last week after Angelina was spotted wearing a diamond ring at a private viewing at the Los Angeles County Museum of Art`s Chinese Galleries.
"Brad had the ring designed last year and made sure it was ready by Christmas because he wanted a romantic Christmas proposal - and he got it," Contactmusic quoted a source as telling Life `n` Style magazine.
"They didn`t announce their engagement sooner because Angie focused so much on promoting `In the Land of Blood and Honey`. She was very busy with the movie and her Oscar campaign. She also worried that the engagement would take over press on her film and detract from that.
"There was some negative press on `Blood and Honey` that bothered her a lot, and she didn`t feel the timing was right. So they waited," the source said.
The pair - who met on the set of 2005 film `Mr. and Mrs. Smith` while Brad was still married to Jennifer Aniston - have children Maddox, 10, Pax, nine, Zahara, seven, Shiloh, five and three-year-old twins Knox and Vivienne - who are all said to be thrilled about the engagement.
"It is a promise for the future and their kids are very happy. There`s no date set at this time," Cynthia Pett-Dante, Pitts`s spokeswoman said of their marriage plans.
The 36-year-old was spotted wearing her engagement ring this week and jeweller Robert Procop - who has previously worked with the actress - revealed he designed it in collaboration with her husband-to-be.
"I can confirm that, yes, Robert Procop did indeed design an engagement ring for Angelina Jolie, designed in collaboration with Brad Pitt," a spokesperson for Robert said.