The billionaire lover of Naomi Campbell, Russian tycoon Vladimir Doronin seems to be enjoying his time with celebrities too much, reported MailOnline.

The pair were extremely loved up at the Indian extravaganza Naomi, 42, threw for the wealthy Vlad for his 50th birthday. But it was reported Thursday that the Vlad was recently spotted at the Rose Bar of the trendy Gramercy Park Hotel in the company of a beautiful blonde.

An onlooker said that the billionaire is a quite serious and hard-working businessman, but is still “enjoying the celebrity lifestyle.”

It’s because of Vlad enjoying the newfound lifestyle a bit too much that him and Naomi are now debating whether to call it quits on their five-year relationship.

Another source in Manhattan who has seen Vlad on town told the MailOnline, "It’s incredible, they were talking about babies and marriage before Christmas and they were so in love, so it’s quite shocking that things have gone downhill so fast."

"For high-profile celebrities like Naomi, red carpets and A-list parties are their job, it’s their business – it’s not what they do for fun.

"But Vlad's now out on the town, he’s hanging around with Leonardo DiCaprio and his whole crowd at all the Manhattan hot spots.

"It’s all a bit baffling."

Naomi Campbell and Vlad are good friends with the Great Gatsby actor. They attended the premier of Leo’s new film last night. The couple was also seen with Leo at a yacht in Miami soaking up the sun.

In August 2010, Leonardo DiCaprio and his supermodel girlfriend, Sports Illustrated cover model, Bar Rafaeli vacationed with Vlad and Naomi on their yacht at the millionaire’s playground of Porto Cervo, Sadinia and then Capri.

They were all spotted together again the following October while on vacation on the Spanish holiday isle of Ibiza and Capri the following year.

Yesterday, a source told Page Six that “Naomi and Vlad have broken up, and he’s been out partying in New York.”

In many ways, according to sources, Naomi and Vlad’s relationship is like a business arrangement and it’s a complex relationship filled with break up and make-ups.

The Naomi Campbell brand brings glamour to Vlad’s hotels and properties, and he treats her extremely well. However, they spend a lot of apart due to work commitments.

The British-born supermodel had numerous work commitments over the past few months with her modeling competition show "The Face" proving to be a huge hit in the US. The show’s across-the-pond edition is currently taping.

The last time Naomi Campbell and Vlad were pictured together was in March on Miami Beach.

Despite their reported separation, however, Naomi is expected to invite Vlad on her 43rd birthday party on May 22 in Ibiza. A source told MailOnline that, "It’s very hard to predict, you never know whether this will be one of their ups and downs or permanent.

"We should know one way or another in the next week or two."

During their five-year relationship, Naomi Campbell and Vlad were rumored to have been engaged several times, but they have always denied the reports since the Russian businessman is still not divorced from wife Ekaterina – despite the fact the pair split in 1999.