Hot new Hollywood couples alert

After they screen-tested for Baz Luhrmann's Great Gatsby remake - with Leo winning the role of Jay Gatsby, and Blake Lively missing out on the part of Daisy Buchanan to Carey Mulligan - the Inception star and the Gossip Girl beauty have been spotted wrapped around one another during a recent trip to Italy. First spotted cosying up on Stephen Spielberg's yacht at the Cannes Film Festival, the pair then took their burgeoning love away from the prying eyes of Leo's very recent ex, supermodel Bar Refaeli, and headed to Portofino - amid whispers it was 36-year-old Leo's broodiness which spelt the end of his five-year relationship with Bar. "Leo sees how happy his friend Tobey Maguire is being a dad and he wants that," spilled a source. "But Bar told him she's just not ready. It crushed Leo." e+ gives them Six months John & Renee Serial lothario, John Mayer is said to have carved yet another A-list notch on his bedpost, after sources say he's moved on to date Renee Zellweger. With insiders whispering that by targeting Renee, John's playing mind games with his ex, Jennifer Aniston - who lost out in another love battle with the Bridget Jones star over Bradley Cooper - others are insisting that it's Renee who's using the singer to heal her recent heartache. "She's looking for a good time with a hot guy," spilled a Hollywood insider. Adding, "Renee doesn't want anything serious right now, and who better to fool around with than Mr Non-Serious himself, John Mayer? Her friends think it's hilarious." e+ gives them Three weeks Leighton & Justin After years spent being on-again/off-again with Drew Barrymore, Die Hard 4's Justin Long has moved on to Gossip Girl's Leighton Meester, with the pair spotted holding hands at dinner in Hollywood, last week. Spied at hip Tinseltown hangout, La Poubelle, a fellow diner, spilled, "They talked to any fan that approached them, they didn't seem to be hiding anything." Adding, "When they left, they held hands as they walked out of the restaurant." e+ gives them Two years Nick & Delta Australian singer, Delta Goodrem has shown she's wasting no time pining for her ex-fiance, Westlife's Brian McFadden, after she was spotted out on a date with Nick Jonas - eight years her junior! Spotted holding hands with 18-year-old Nick at Hollywood's Arclight cinema, 26-year-old Delta had previously gushed about the Jonas Brother back in March, when she Tweeted a pic of the pair with their arms around each other and wrote, "Loved creating with the incredibly talented @nickjonas". But sources have said the relationship wasn't behind her split from McFadden after four years together, who praised her as a "living angel" after their break-up. And after the pair was spotted holding hands, loved-up Nick Tweet-gushed, "I feel so blessed." e+ gives them One year Weddings & engagements! It's a total love-fest in Hollywood right now… Wedded bliss: Tony ties the knot Dallas Cowboy Tony Romo beat his ex, Jessica Simpson, up the aisle to wed Candice Crawford in Dallas, last weekend. Candice, a former beauty queen-turned-TV presenter and the sister of Gossip Girl hottie Chace, and Tony wed at Arlington Hall, which saw her Badgley Mischka-clad bridesmaids mingle with the who's who of the NFL, and guests enjoy short ribs and pizza, before walking home with goodie bags containing Kiehl's beauty products and mini bottles of Moet. Shock proposal: Kim's incredible 20.5 carat rock! After six months together, Kim Kardashian's New Jersey Nets NBA player boyfriend, Kris Humphries, has popped the question, presenting the reality TV star with a custom-designed 20.5 carat diamond ring. "I knew I wanted it to be big," Kris told People. Erm, achieved! And an over-the-moon Kim, 30, added, "I didn't expect this at all." And the break-ups… The stars who are ditching and splitting... Engagement Off! Ginnifer & Joey He's Just Not That Into You star, Ginnifer Goodwin last week split from her fiancé, actor Joey Kern, just weeks after she gushed in an interview, "[I] want a life full of little Joeys." Gin, 32, and Super Troopers actor Joey, 34, called off their six-month-long engagement, with pals staying, "They intend to stay friends." Ditched! Cheryl & Derek After being unceremoniously dumped as a judge from the US version of X-Factor, Cheryl Cole has also done some ditching herself, splitting from her man of one year, Dancing with the Stars' Derek Hough. "He can't help feeling that she used him to get publicity in Hollywood," a pal told Star. Tatts it! Jesse & Kat He may be busy promoting his tell-all book, American Outlaw, but sources say Jesse James has also been busy splitting from his fiancée, American tattoo artist, Kat von D. "They were supposed to be married months ago," said Liz Friedman, a former shop manager on Kat's reality show. "There's no longevity there… Jesse [is] kind of rebounding from Sandra."