The 26-year-old actor reportedly dumped the actress, who he reconciled with in October 2012 following a brief split after she cheated on him with her 'Snow White and the Huntsman' director Rupert Sanders.
His friends are said to be secretly relieved he has ended the four-year relationship, reported Daily Express online.
"No one would ever have told him what to do. But some people felt he never gave himself time to deal with what happened and heal. They think he has made the right choice," a source said.
The screen heartthrob is said to have finally made his mind up following a difficult Christmas in his native UK with his 'Twilight Saga' co-star Kristen and his family.
"Rob thought it would be good for he and Kristen to visit his family in the UK over Christmas and New Year, but things were very frosty.
"Rob's family, especially his sisters, have found it hard to forgive the hurt and humiliation Kristen has caused him," the source added.