They called off their engagement in 2022, less than a year after announcing the happy news with a loved-up photo on Instagram.
But are Prince Louis of Luxembourg and his ex-fiancée Scarlett-Lauren Sirgue back on once again? The pair were pictured looking cosy with one another at an event in Paris last Thursday.
Their joint outing to the annual awards for The Association for French Influence, which celebrates French talent, sparked speculation online about a possible reconciliation between the duo.
It's not the first time such rumours have swirled on social media, after the couple were pictured huddled up together at composer Omar Harfouch's concert at the Institut du Monde Arabe in Paris in February.
The royal, 38, and French lawyer Scarlett-Lauren sent online rumours swirling at the time, with some speculating that the pair were now 'back' on. However, it is not clear whether the pair have officially reignited their romance.
Sporting an elegant black ensemble, complete with a pleated skirt and a gem encrusted jumper, as well as knee-high boots, Scarlett-Lauren was all smiles as she stood with her arm around the Prince.
Dressed to impress in a navy blazer, black trousers, white crisp shirt and a red statement tie, Louis, the third son on Grand Duke Henri and Grand Duchess Maria Teresa of Luxembourg, looked equally happy to be by the French lawyer's side.
'Well maybe they have figured out the differences they had and reconciled?' one royal enthusiast questioned online after the image was shared by Grand Ducal Family of Luxembourg fan account.
'Nobody knows for sure. There are some rumours going around about a possible reconciliation, but for now, it's just speculation,' another fan replied.
MailOnline has reached out to the Grand Ducal Family of Luxembourg for comment. Prior to their outing in February, it is understood that the couple hadn't been pictured together since announcing their break-up two years prior.
In 2022 - less than a year after announcing their engagement with a loved-up photo on Instagram - the couple announced that they were breaking up.
They told the French magazine Point de Vue that they had put an end to their four-year-long romance due to differing life goals.
The couple announced they were engaged on April 6 2021 with a relaxed picture accompanied by official snaps with Louis' parents, Grand Duke Henri and Grand Duchess Maria Teresa.
They vowed to remain friends, and added they still have a lot of love for each other and each other's families.
Prince Louis was previously married to Tessy Antony, whom he shares two sons with, Prince Gabriel of Nassau, 18, and Prince Noah of Nassau, 17. The couple divorced in 2019.
Speaking to the French publication, Louis said: 'We have been in love with each other for the past four years.'
In 2022 - less than a year after announcing their engagement with a loved-up photo on Instagram (pictured) - the couple announced that they were breaking up
'We always have tried to be completely honest with each other. Even when this honesty hurts us like today, we are more than ever convinced it is crucial.'
'Thinking about things a lot and getting to the bottom of it, we eventually admitted that as a family, as parents, our visions are too divergent. Our ambitions in life are too different,' Scarlett added.
Scarlett added that Louis’ family had given her a warm welcome and added that even though their loved ones are saddened by the news, their affection for her wouldn’t change.
Prince Louis said Scarlett is still his best friend, and that she enjoys a close relationship with his parents, siblings and his two sons, Gabriel and Noah.
He added he has explained the situation to his sons, and that although they are sad, they know they'll continue to see Scarlett and can always count on her.
He also he still holds Scarlett's family dear and that the couple cherish their close friendship and their tight bond.
In the same interview, Prince Louis explained that when the couple got engaged in 2021, they had gone over how Scarlett would join the royal family and the concessions that would have to be made, which he said had not been an issue for either party.
The couple have issued an official statement, in which they said: 'We have decided not to pursue our romantic relationship, while remaining deeply bound by friendship and tenderness.'
The couple, who work for the same company, had been dating for the past four years and have said they intend to remain friends (pictured in November 2018)
Prince Louis (pictured in 2020) said Scarlett is still his best friend, and that she enjoys a close relationship with his parents, siblings and his two sons, Gabriel and Noah.
Born in Bordeaux on 8 August 1991, Scarlett-Lauren is the youngest child of lawyers Pierre Sirgue and Scarlett Sigrue.
At the beginning of her career, she worked alongside her mother in Family Law, before decided to focus more specifically in Victims' Law.
Scarlett-Lauren works for the firm which was founded by her parents, which is also where Prince Louis works as a mediator.
Louise was previously married to Tessy Antony de Nassau, with whom he shares his two sons.
The entrepreneur, who is now married to hunky Swiss businessman Frank Floessel, has talked candidly about the pressures of royal life in the past.
Last year, she told Hello magazine that it 'took a long time' after her divorce, when she was stripped of her royal titles, explaining: 'After every relationship it takes a while to heal when the heart has been broken.'
'It has been really, really wonderful for me to realise that I am able to trust and love again. It's nice to see that life goes on.'
Louise was previously married to Tessy Antony de Nassau, with whom he shares his two sons. Both pictured in 2012
Tessy went on to reveal how she is 'very happy' that her ex-husband Prince Louis maintains a close bond with their sons, despite the fact they couldn't see each other during quarantine.
Tessy said her son's 'love and trust' with their father had 'become stronger' because of the separation during the pandemic.
Tessy has previously told how her family 'suffered greatly' when she became a princess in 2006 after marrying Prince Louis, whom she met in 2004.
She had joined the Luxembourg Army in 2002 at the age of 18, rising to the rank of corporal. Two years later, when she was one of a handful of female UN peacekeepers in Kosovo, she met Prince Louis, who was visiting the army.
His family only became aware of their love affair when Tessy fell pregnant and gave birth aged 19, unmarried, in September 2005, providing Grand Duke Henri with his first grandson. The pair pictured in 2012
It infuriated the royal family, and Prince Louis renounced any claim to the title of Grand Duke due to the constitutional crisis they had created by having a child out of wedlock.
When Tessy married Prince Louis in September 2006, six months after giving birth, in a modest country church wedding, the Grand Duke stripped her of any claim to his title.
The couple's fairytale marriage broke down in 2016, and they were granted a decree nisi in February 2019.