Sienna Miller and Balthazar Getty, who split-up earlier this month, were spotted together in London yesterday.
An onlooker said, "We drove past them and they looked very together. Sienna looked really pretty and so happy".
Sienna's love of partying is believed to have been the prime cause for her split from Balthazar, who is married with four children.
A close source said, "Sienna is only 26 and loves to go out. At first Balthazar was excited by her beauty but eventually realized he should be back with his wife, and that Sienna represented a phase from another point in his life".
