Downton Abbey star Michelle Dockery has ended her fling with Joseph Millson because she is not really for a long-term relationship.

The actress, who plays Lady Mary in the award-winning period drama, got together with Millson, who appears in medical soap Holby City, after splitting with architect Trent Davies.

Devastated Millson has opened his heart in a series of plaintive tweets as he tries to come to terms with the split.

michelle dockery

Dockery has split from fellow actor Millson

In one post, he wrote: "Just wait for someone worth being in a relationship with, stop ­wasting your time on the ones who don't deserve you."

A friend of Millson, who plays trauma registrar Luc Hemingway, told the Sunday Mirror: "He's heartbroken. The split was unexpected and it's still very raw for him."

He had reportedly left the mother of his two children to be with Dockery, who was on the rebound after ending her three-year relationship with Davies.

A source told the paper: "Michelle was really sad when it didn't work out with Trent. She really believed the relationship would go the distance and thought there was a chance they would get married. But it wasn't to be.

"All of her friends were shocked when she and Trent split. She started dating Joseph, but called it off after a few months. She wasn't ready for a new relationship."

Only last month Millson and Dockery were in Los Angeles to attend the Emmy Awards, where she was nominated for Outstanding Lead Actress in a Drama Series.

Talks are underway to turn Downtown Abbey into a Hollywood movie after the worldwide success of the TV show.

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