Brad Pitt was seen hanging out again with Ines de Ramon in Hollywood, California over the weekend of Dec. 18, which only fuelled rumours that they are dating. The "Bullet Train" actor rang in his 59th birthday on Sunday with the recently-divorced 32-year-old vice president of Anita Ko Jewellery. They were spotted arriving in the same car at an establishment where they had his birthday bash.

Photos from Page Six showed the pair looking happy together. They shared smiles and appeared to be relaxed in each other's company. Pitt dressed casually for the occasion in jeans and a striped button-down shirt, while de Ramon was in a camel coat with fur trim.

Rumours that they are dating started when they were spotted backstage at a Bono concert in Los Angeles' Orpheum Theatre in November. Pitt was photographed with his arm around de Ramon's shoulder and he even introduced her to his friends Cindy Crawford, her husband Rande Gerber, and to fellow actor Sean Penn. They were reportedly holding hands at the venue.

Last week, a source claimed that the Hollywood star is "smitten" with de Ramon and that he "wasn't expecting to find someone so extraordinary" like her. But they are "not officially dating."

They have reportedly "been spending time together as friends and really enjoy each other's company." In the process, they have become "great friends" and are now just waiting to see what "blossoms from there." It has also been claimed that they will be spending New Year's Eve together.

Another insider added that "it's not serious yet" between them, but "he's comfortable and they're having fun together." Pitt reportedly enjoys de Ramon's company so much that according to People, he even invited her to the premiere of his movie "Babylon" last Thursday, and they were at the after-party together.

Pitt finds her "fun and social" and that they "do solo dates" as well as "group dates with friends." It is said that de Ramon also finds the actor "very sweet." However, they have yet to comment on claims that they are in a romantic relationship. One thing the two share in common is that they are both divorced. Pitt was married to actress Angelina Jolie and de Ramon recently split from "The Vampire Diaries" star Paul Wesley.

Brad Pitt
Brad Pitt (Photo by Amy Sussman/Getty Images