Kate Winslet promised she would "never let go" in Titanic, but in real life, Leonardo DiCaprio has done just that.

The actor, now 37, was noticeably absent from the worldwide premiere of Titanic 3D in London March 27. Winslet, 36, glided down the red carpet in a Jenny Packham dress, where she caught up with director James Cameron and costar Billy Zane, 46.

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DiCaprio, on the other hand, "is glad he got out of going to the Titanic premiere in Europe," a source tells Us Weekly. "He understands what it did for his career and is grateful, but he has moved so far forward and to another level. To bring Titanic up again just isn't in his mindset. It took him a long time to move away from that character to get where he is."

The source adds that there "are no hard feelings" between DiCaprio and Cameron, 57. "They are still good and have talked recently."

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During a recent interview with iTV's Daybreak, Winslet said it was fun to see how much she and DiCaprio have grown since starring in the 1997 blockbuster that made them bonafide movie stars. "We do look very different," she said. "We were 21 and 22 when we made that film. You know, he's fatter now -- I'm thinner."

Titanic 3D is in theaters Friday.

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