Kevin Mazur/WireImageWhile celebs like Robert Pattinson and Kristen Stewart were ringing in Memorial Day weekend in Cannes, Beyoncé was showing off her amazing post-baby bod at her comeback concert in Atlantic City.
But news of the superstar singer getting her groove on in barely-there costumes wasn't the only thing brewing this weekend.
Check out the deets on which stars won big at Cannes, Justin Timberlake and Jessica Biel's engagement party, and much more, right here!
• Beyoncé Returns: The Bootylicious One kicked off her Memorial Day weekend concert looking amazing in barely there costumes just five months after giving birth to daughter Blue Ivy.
• Engagement Party: Timberlake and Biel celebrated their upcoming nuptials with a big engagement party Saturday, hobnobbing with the likes of Ellen DeGeneres and Lance Bass at the outdoor evening affair.
• Big Winners: Not even flicks with Hollywood star power like Brad Pitt's Killing Them Softly could stop Michael Haneke from taking home the top prize at the Cannes Film Festival Sunday; the filmmaker won the coveted Palme d'Or for his drama Amour.
• Show Stopper: Lady Gaga was forced to cancel her upcoming concert in Jakarta, Indonesia, after the "Born This Way" crooner faced harsh criticism and threats from Muslim protesters.
• Box Office Blast: Men in Black 3 topped this weekend's box office with $55 million, followed by The Avengers at $37 million and Battleship at $10.8 million.
• Rumor Control: Simon Cowell slammed stories that claimed Britney Spears stormed off the set of the X Factor, insisting "there was no walking off."
• Baby Bumpin': Reese Witherspoon hit the Cannes Film Festival for the premiere of Mud Saturday, showing off her baby bump in a black, tight-fitted LBD dress.
• Baby Mama Drama: Flavor Flav is facing a 180-day jail sentence for allegedly failing to pay more than $111,186 in child support payments to the mother of three of his seven children.
• Happy Anniversary! Jay Leno celebrated his 20th anniversary on The Tonight Show Friday, joking that in the time he's been host, "we've seen a lot of stars come and go from the program…including me!"
• Idol Engagement: Ace Young dished to E! News exclusively about how he was able to pull off his proposal to fellow American Idol alum Diana DeGarmo.
• Honorable Mentions: Robert De Niro was awarded with an honorary doctorate of fine arts during Bates College's commencement ceremony Sunday in Lewiston, Maine.
• Tying the Knot: Cynthia Nixon and longtime partner Christine Marinoni married Sunday in New York, three years after they got engaged at a rally to support gay marriage in the Big Apple.
• Reunited: Friendly exes Jennifer Lopez and ex-hubby Marc Anthony walked on stage holding hands in Las Vegas Saturday at the taping of their Q'Viva! The Chosen show.
• Paparazzi Trouble: A paparazzo is claiming he got into a physical altercation with Justin Bieber after he attempted to snap photos of the Biebs and his girlfriend Selena Gomez in Calabasas, Calif., Sunday afternoon.
• Flight Trouble: Kim Kardashian claimed some "sentimental" items were stolen from her luggage on her flight back from the Cannes Film Festival, tweeting that she was "very disappointed in British Airways" for the item-lifting snafu.
• Creepy Crypt: The entrance to a private crypt that once held Elvis Presley's body will be auctioned off next month. The lot will go on auction for a starting price of $100,000.
• Soccer Celebrity Slam: Gordon Ramsey and Will Ferrell played in a U.K. celebrity soccer match for UNICEF, but both stars were injured during the game. Chef Ramsey was taken to the hospital and carried off the field on a stretcher, but he is expected to make a full recovery.
• Blissfully Blinging: Keira Knightley showed off her stunning engagement ring while on a romantic stroll with her fiancé James Righton. The adorably affectionate couple recently announced their engagement after dating for 15 months.