They enjoyed an on and off romance for over five years, which finally ended in 2010.
But exes Prince Harry and Chelsy Davy have managed to remain close.
The pair, who move in the same social circles, were spotted on Thursday partying in London together following Harry’s return from the US.
CLICK ON PHOTO FOR FULL GALLERY
They both stayed at exclusive Chelsea club The Brompton until 2.30am, before leaving separately.
Club-goers said the couple greeted each other warmly inside the venue.
The former lovers were joined by a few famous faces including Dizzee Rascal, David Haye and Louis Walsh.
Harry, 27, opted for smart in a suit and black shoes but gave the ensemble a casual edge by forgoing the tie and leaving his top button undone.
Chelsy, 26, looked festive in a red mini dress with black heels.
The Prince has just finished two months of intense military training in California and Arizona.
Earlier in the day Harry and Chelsy both attended a memorial service for pal Henry Van Straubenzee, who died in a car crash in 2002.
A close friend of princes Harry and William, this year marks the third annual carol service in his honour, held at St Luke's Church in Chelsea.
During the ceremony, Harry paid tribute to his close friend, telling the 800-strong congregation, "It's never easy losing someone close to you" – and when it is family it is "even harder."
He went on to praise Henry's "love of life and sense of fun" and sometimes "inappropriate sense of humor".