May was a busy time for snap-happy social stars, with the 2013 Met Gala kicking off the beginning of the month and Memorial Day launching the unofficial start of Summer — and bikini selfie season. Aaron Paul got married in California, while Kristen Stewart , Cameron Diaz , Sienna Miller , Gisele Bündchen, and many more shared a behind-the-scenes look at the Met Gala. Justin Bieber  reignited romance rumors with Selena Gomez  when he posted a picture of them snuggling in his hotel room, while Drake announced his cameo in the upcoming Anchorman: The Legend Continues by sharing a photo of himself in costume with Judd Apatow. Meanwhile, stars like Rihanna , Bar Refaeli , and Lea Michele  showed skin on their social networks while vacationing and modeling Summer clothes.
Click through to see the rest of this month's cutest celebrity candids, and be sure to follow POPSUGAR on Instagram , Facebook , and Twitter !
Aaron Paul kicked off his wedding  weekend when he shared a photo of soon-to-be-wife Lauren Parsekian giving him a kiss on their way to their rehearsal dinner.
Rihanna  rocked a denim-on-denim (on denim) look from her River Island  collection.
Stella McCartney  posed with her models for the night, Cameron Diaz  and Kristen Stewart .
Justin Bieber  shared a shirtless  photo — with on-again, off-again girlfriend Selena Gomez  — on his feed.
Designer Prabal Gurung shared his excitement to meet Jennifer Lawrence at the Met Gala.
Bar Refaeli  showed off her bikini body during a beach day in her native Israel.
Doutzen Kroes got wacky in the waves with her husband, Sunnery James.
Kim Kardashian  showed off her legs with a fellow partygoer.
Candice Accola showcased her shiny new engagement ring.
Drake posed in costume with one of his "heroes," Judd Apatow, on the set of Anchorman: The Legend Continues.
Miley Cyrus , Emma Roberts, Rita Ora, Cara Delevingne, and more got the Met Gala afterparty started.
James Franco  posed with his As I Lay Dying castmates before the film's premiere at the Cannes Film Festival.
Nicole Richie  stood back-to-back with her 14-year-old sister, Sofia — how gorgeous are they?
Jessica Alba  got "Vadered" by a friend during a trip to Singapore.
Gisele Bündchen snapped a bikini pic while relaxing at a tropical resort.
Doutzen Kroes posed with a group of French police officers before hitting the red carpet in Cannes.
Paul Wesley  and Ben McKenzie went on a "romantic date" to see Behind the Candelabra.
Sienna Miller  shared a kiss with her model pal Cara Delevingne after the Met Gala.
Gisele Bündchen and Tom Brady  made their way to the Met Gala in stunning fashion.
Jessica Alba  snuggled with her daughters, Honor and Haven.
Chrissy Teigen and John Legend  made a picture-perfect couple at the White House Correspondents' Dinner.
Julianne Hough and Nina Dobrev  indulged after a night of high fashion at the Met Gala.
Ashley Tisdale  and Vanessa Hudgens  celebrated Memorial Day together at a backyard BBQ.
Miley Cyrus  hit the recording studio.
Kim Kardashian  snapped a Met Gala candid with Beyoncé and Solange Knowles.
Mariah Carey  and her twins, Moroccan and Monroe, saddled up for a shuttle ride.
Before the Met Gala, Stella McCartney  spent time with her close friends Chris Martin  and Jay-Z.
Mindy Kaling wrote some checks during her day off.
Paris Hilton  posed in a one-piece swimsuit.
Hugh Jackman  and his wife, Deborra-Lee Furness, posed with Oprah Winfrey  after an OWN TV interview.
Miley Cyrus  snapped a photo while hanging in bed with her mom, Tish, with the caption "Nothing a little mommy time can't fix."
Cristiano Ronaldo posed with Rihanna  backstage at her concert.
Mario Lopez's daughter, Gia, gave her mom, Courtney Mazza, a quick touch-up on the set of Extra.
This photo of Emmy Rossum in her Las Vegas hotel-room bathtub seriously had us in stitches.
Minnie Driver  caught "a little tiny Dorado" while fishing in Mexico.
Jessica Biel  gave a sneak peek of her gown before arriving at the Met Gala.
Emma Watson  had to get some help taking off her shoes after a long day at Cannes.
Miranda Kerr  showed off a chic pair of 3D glasses while attending a screening of The Great Gatsby.
Lena Dunham snapped a pic of her new lizard-print tee.
Snoop Lion linked up with Tony Bennett for a music charity event.
Eva Longoria  shared this photo of the view from her hotel balcony in Cannes.
Rita Ora chatted with Gwen Stefani  and Gavin Rossdale  while checking out the Met Gala exhibit.
Carly Rae Jepsen showed off her new red locks!
Alessandra Ambrosio checked out the fireworks at the de Grisogono party during the Cannes Film Festival.
Rashida Jones got a private cooking lesson from French chef Jean Imbert.
Chrissy Teigen shared a photo from the "best wedding  ever."
Cat Deeley showed off her cheerleading skills in the pool with some pals.
Rachel Zoe  posed with mom-to-be Fergie .
Kevin and Joe Jonas  took in a NY Yankees game together.
Britney Spears  chatted with Mario Lopez backstage at KIIS FM's Wango Tango.
Rebel Wilson celebrated reaching one million Twitter followers with a snack.
Lea Michele  showed off her bikini body while vacationing with her boyfriend, Cory Monteith .
Chrissy Teigen lounged in a pair of leather pants before her appearance on VH1 Buzz.
Tyrese Gibson, Vin Diesel, and Ludacris posed together during the red carpet premiere of Fast & Furious 6 in London.
Miranda Kerr  flashed a peace sign (while sporting a peace sign sweatshirt).
Sofia Vergara enjoyed eating "a big Chinese shrimp" during her trip overseas.
Kim Kardashian  hugged pop icon Madonna  at the Met Gala.
Miranda Kerr  shared an adorable photo while hanging out with her son, Flynn, on Mother's Day .
Jennifer Lopez  premiered her new single on a radio show.
Michael Kors  posed with his girls for the night, Jennifer Lopez  and Miranda Kerr .
Kelly Osbourne gave Jennifer Lopez 's behind a thumbs-up at the Met Gala.
Mark Ruffalo  headed to the NYC premiere of Now You See Me with his family.
Katy Perry  made funny faces at Gerard Butler  inside the Met Gala.
Kathie Lee Gifford and Hoda Kotb couldn't keep their hands off of Bill Hader.
Zooey Deschanel  shared this sweet snap while relaxing with her pup.
Victoria Beckham  got her hair and makeup done before a photo shoot.
Aaron Paul had a real rollicking time at a Rolling Stones concert and even posed backstage with Ronnie Wood and Keith Richards.
Jesse Tyler Ferguson teased "a fun little project" with his friend Brad Goreski.
Rob Lowe  sported some scruff while sharing this "selfie at sea."
Nick Lachey  reunited with the boys of 98 Degrees for a visit to Watch What Happens Live.
Matthew Morrison  was dressed up for a black-tie event with Homeland's Damian Lewis.
Demi Lovato posed with her new fellow X Factor judges Paulina Rubio and Kelly Rowland.