Julianne Hough

When the biggest names in Hollywood, music and fashion get together, there are bound to be some friendly match-ups, and that's just what happened at today's Costume Institute Benefit. Stars mingled with their famous friends, walked the carpet with their designing pals, and brought their significant others to celebrate the Punk: Chaos to Couture exhibit at the Metropolitan Museum of Art. Go ahead and check out the fun duos at the Met Gala, including Jennifer Lawrence's Hunger Games reunion with Elizabeth Banks and Nicole Richie's run-in with Julianne Hough and Jaime King.

Justin Timberlake welcomed his celebrity pals to a special show at NYC's Roseland Ballroom last night. The performance, which was organised to celebrate his new deal with MasterCard and billed as one of the credit card's "Priceless" events, brought out JT's SNL pals Andy Samberg and Jason Sudeikis. Justin's wife, Jessica Biel, was also in the wings cheering on her husband. Andy and Jason had their ladies too — they brought their respective fiancées, Joanna Newsom and Olivia Wilde. Also out for the performance were Julianne Hough, Uma Thurman and Brooke Shields.

The Cinco de Mayo show gave Justin a chance to perform music from his latest album, The 20/20 Experience, which he recently announced will be followed up by The 20/20 Experience Part 2 in September. He sang plenty of his old songs too, from "Like I Love You" to "Cry Me a River" and "Senorita." Justin joked with the crowd, with quips like, "You're at an eight and a half. If you be honest with me, I'll be honest with you." He also asked, "Is anybody drunk yet?" After hearing some cheers, he added, "Good for you!" His frequent collaborator Timbaland emerged toward the end for a rendition of "SexyBack." It seems Justin had as great a time as the fans. He tweeted last night, "Thank you NYC and Roseland Ballroom! Had so much fun tonight. Lets do it again soon."

It was a fun-filled seven days for our favourite celebrities this week, with movie premieres and stylish parties dominating the agenda. Kate Moss and Stella McCartney showed us how it was done in the '80s with a wild surprise party for a close friend, while Australian Princess Mary was celebrating in a very different way as Prince Willem-Alexander took the Danish throne after his mother's abdication. The Great Gatsby and Star Trek: Into Darkness premieres ensured we were supplied with plenty of red carpet sightings, including Leonardo DiCaprio and Zoe Saldana, while on set in New York, Girls stars Lena Dunham and Adam Driver got us excited for the third season. And on a beach in Miami? Julianne Hough and Nina Dobrev braided each others' hair. Cute. Click through to see all the pictures from this busy week!

Between new haircuts, updated styles, slicked locks and lots of ombré, hair certainly stole the show in this week's celebrity beauty round-up. Nicole Richie set the pace with her first official appearance since she took a trip down fringe lane (hubby Joel Madden didn't notice — ah, men), while Kate Middleton mixed things up with wavier hair than usual (not to mention that pregnancy glow). But it wasn't all about hair. Isla Fisher totally stole the show at The Great Gatsby world premiere, thanks to her bright red lips and cats-eye liner — see that look and more when you click through!

Julianne Hough donned a bright red Carolina Herrera number to step out for the EIF's Unforgettable Evening event in support of the Women's Cancer Research Fund at the Beverly Wilshire hotel in LA last night. She was joined by a host of other stars for the charitable evening, including Kylie Minogue, Chelsea Handler, Rita Wilson, Amber Valletta, Angie Harmon, and Lisa Kudrow. Big names from the fashion industry like Carolina Herrera, Tommy Hilfiger, and James Ferragamo were also in attendance for the night out. Funnygirl Chelsea, who was accompanied by her boyfriend, André Balazs, was the life of the party as she made the rounds on stage and visited different tables throughout the dinner. Julianne and Chelsea are not the only stars to support the cause. Next weekend, Halle Berry and Julie Bowen will be among other A-listers to step out for the EIF's Revlon Run/Walk For Women in LA, which benefits women's cancer research.

Aside from her big night out, it was a relaxing week for Julianne, who joined pal Nina Dobrev in Miami over the weekend. Julianne and Nina donned bikinis for a relaxing beach getaway that included fun in the ocean and poolside lounging. Nina has been a supportive friend to Julianne, who broke up with Ryan Seacrest back in March, and the girls turned up at a Lakers game together right after Julianne's publicised split.

White pumps aren't the only shoes having a major moment in Hollywood — metallic pumps have also been taking over famous feet as of late. So far we've spotted the likes of Katy Perry, Miranda Kerr, Emmy Rossum, Olivia Munn, Julianne Hough, and more of the trendsetting pack shining up their red carpet style with gold and silver heels. What's great about this trend is that it has the ability to instantly dress up any ensemble, especially denim and your favourite dresses. Step inside to witness 15 celebrities working the metallic-pump trend, then be inspired to jazz up your own shoe wardrobe with metallic footwear.

Nina Dobrev and Julianne Hough continued their girls’ getaway in Miami today. The actresses and friends have spent the weekend soaking up the sun on the beach or at the pool at their hotel. They’ve been sun-safe and were spotted rubbing sunscreen on each other’s backs, and securing the other’s bikini straps. They also took turns getting their hair braided while sipping on refreshing beverages.

The holiday was long overdue for The Vampire Diaries star Nina, who tweeted before arriving in Miami, “10 months of shooting... Time to play!” Julianne has also been active on her social media accounts while on vacation, and shared a photo of the girls on Instagram with a spread of sweet treats in front of them, captioning the picture, “Whoopsies!”