Jennifer Lopez and Marc Anthony arrive to celebrate Jennifer's 40th birthday in NY

Jennifer Lopez (L) and Marc Anthony arrive to celebrate Jennifer's 40th birthday at the Edison Ballroom on July 25, 2009 in New York City. Celebrity Sightings In New York - July 25, 2009 Streets of Manhattan New York, NY United States July 25, 2009.

Jennifer Lopez and Marc Anthony watch MLB interleague baseball game

Singers Jennifer Lopez and Marc Anthony (L) sit next to each other as they watch the New York Mets MLB interleague baseball game with the Tampa Bay Rays in New York June 21, 2009.

Jennifer Lopez and Marc Anthony arrive at the "Noche de Ninos Gala"

Singer Marc Anthony (L) and wife actress Jennifer Lopez arrive at the "Noche de Ninos Gala" benefiting Childrens Hospital of Los Angeles at the Beverly Hilton Hotel on May, 9, 2009 in Beverly Hills, California.

Jennifer Lopez keeps jewels

Singer Marc Anthony and his wife Jennifer Lopez talk on stage before performing together at the Western Regional Inaugural Ball in Washington January 20, 2009.

Jennifer Lopez has kept $50,000 worth of diamonds she borrowed last week.

The singer-and-actress wore the Robert Mouawad jewellery to the launch of Andrea Lieberman's fashion line ALC, in Beverly Hills, and while other guests have given back the precious jewels, Jennifer has kept hers.

A source told the New York Post newspaper: "We received a call from her manager informing us that Jennifer was going to keep the jewellery. As far as Mr. Mouawad is concerned, Jennifer can have whatever she wants, but a premature demand seemed presumptuous. He will lose no sleep over $50,000, and frankly, Jennifer's endorsement is priceless."

Jennifer's manager Benny Medina insists the 39-year-old star was given the jewellery along with clothes from the ALC fashion line in return for hosting the event.

Medina said: "There was no demand whatsoever. There was an offer. It was very clear. It was agreed she would be given the entire collection of jewellery and clothes.

"She was the only celebrity whose name was on the invite. She would have done it for nothing. But this was how it was presented. It was quite a generous offer."

Jennifer is not the only star to have encountered problems while wearing expensive borrowed jewels.

In 1993, Sharon Stone was sued by Harry Winston Inc. after she failed to return a $400,000 necklace. The 'Basic Instinct' actress claimed she thought the jewellery was a gift.

Paris Hilton had to pay out $100,000 after losing the lavish Kwiat bracelet she wore to the Oscars in 2003. The blonde socialite said the trinket was stolen from a friend's car.

Jennifer Lopez and Marc Anthony to announce split Valentine's Day?

Musicians Marc Anthony and Jennifer Lopez arrive at the 66th annual Golden Globe awards in Beverly Hills, California January 11, 2009.

Jennifer Lopez arrives at the 66th annual Golden Globe awards in Beverly Hills, California January 11, 2009.

Jennifer Lopez and Marc Anthony to announce split Valentine's Day?

Marc Anthony and Jennifer Lopez will end their 4.5 year marriage in February, according to a scoop featured in Monday’s edition of the NY Daily News.

A friend of the couple tells the tab: “Marc and Jennifer are planning on announcing their divorce right after Marc’s show at Madison Square Garden on Feb. 14. Jennifer is planning on joining Marc onstage for a surprise duet. Things haven’t been right for a while now, and they thought it would be a bittersweet farewell.”

Marc and Jennifer, parents of ten month-old twins Max and Emme, renewed their wedding vows in an impromptu ceremony in Las Vegas last October, but the ritual has done little to remedy the couple’s rumored rift.

“They’re definitely planning a clean break in February,” the source said.

Jennifer is said to resent Marc’s attitude to their children and his attempts to reinvent her as a Latin star while a source close to Marc added: “Marc’s ready to move on. The fighting has been too much for him to handle lately.”

A spokesperson for the couple declined to comment on the rumours.

Lopez attends the inauguration of Puerto Rico's Governor

Singers Marc Anthony (L) and Jennifer Lopez attend the inauguration of Puerto Rico's Governor Luis Fortuno in the North wing of the Capitol Building in San Juan January 2, 2009.

Jennifer Lopez's nanny no

Jennifer Lopez's nanny no

Jennifer Lopez and her husband Marc Anthony refuse to hire a nanny to look after their twins.

Singer and actress Lopez and husband Anthony arrive for the Metropolitan Museum of Art Costume Institute Gala in New York.

Marc insists Jennifer prefers to care for three-month-old Max and Emme herself, but he is expected to help out as much as possible. He revealed: "She expects me to help and she makes no bones about it. I get the late shift! I usually get from 10pm onwards because we don't have a nanny. From 10pm to 8am, that's my shift. It's just us man. We're figuring it out and having a great time."

Marc insists singer-and-actress Jennifer is planning to return to work soon, but at the moment she is totally devoted to her babies. The singer - who has three children from two previous relationships - added to 'Access Hollywood': "She has three movies lined up and she's eager to go back to work, but the babies have been a blessing all the way around and she's just amazing. She's an amazing mom and I'm so proud of her. She's a gem to watch in action."