This week our favorite stars were all about letting loose and having a good time — at work and at play. Selena Gomez  showed off her hot bikini body in Miami, while Matt Lauer used Today's Halloween  episode to prove he's man enough to rock an iconic swimsuit. President Barack Obama and First Lady Michelle Obama handed out candy to children visiting the White House, and Kim Kardashian  had fun at Six Flags. Meanwhile, Orlando Bloom  and Miranda Kerr  showed us why they will always be family. Check out all that and more in this week's best pics!
Gisele Bündchen made her first runway appearance  in over a year at the Colcci show at São Paulo Fashion Week in Brazil this week.
Miranda Kerr  and Orlando Bloom  showed a united front  when they took their son, Flynn, on a walk in New York on Saturday morning, following Friday's announcement that they've separated after three years of marriage.
Angelina Jolie  held hands with Knox when she brought her little ones along to shop  for Halloween  decorations on Saturday.
The president and first lady personally handed out candy  at the White House on Thursday.
Blake Lively  spoke on stage  while being announced as the new face of L'Oréal in Paris on Tuesday.
Heidi Klum  pulled out all the stops  for her elderly woman costume in NYC on Thursday.
Cristiano Ronaldo unveiled a revealing ad campaign  for his CR7 underwear line in Madrid, Spain, on Thursday.
Kim Kardashian  was texting during a roller-coaster ride  with Bruce and Kris Jenner at Six Flags Magic Mountain on Tuesday.
Penn Badgley  embraced the "no shirt, no problems" philosophy when he hung out with friends  at Echo Park in LA on Sunday.
Matt Lauer dressed up as C.J. Parker , Pamela Anderson's character on Baywatch, for Halloween  on Today.
Selena Gomez  showed off her bikini body  during a break from her tour in Miami, FL, on Monday.
Olivia Wilde  debuted her baby bump  at the International Women's Media Foundation's annual Courage in Journalism Awards in Beverly Hills on Tuesday night.
Friends Sandra Bullock  and Melissa McCarthy  dressed up as fishermen  when they took their children out trick-or-treating in LA on Thursday night.
Jessica Simpson  celebrated Halloween  with a group dinner in LA on Thursday.
Paris Hilton  pretty much became Miley Cyrus  at the Playboy Mansion's Halloween  party on Saturday.
Gabrielle Union  showed us she doesn't age  when she hung out courtside to support her boyfriend, NBA player Dwyane Wade, at his Miami Heat kickoff game in Florida on Tuesday night.
Michelle Williams  walked with her daughter , Matilda Ledger, in New York on Monday. It was Matilda's eighth birthday.
Amanda Seyfried  and Justin Long  made their first joint event appearance  and hung out with friends at the LAByrinth Theater Company's annual celebrity charades benefit in NYC on Monday.
Emily VanCamp filmed a wedding scene  with Gabriel Mann on the set of Revenge in LA on Tuesday.
Zoe Saldana  and her husband, artist Marco Perego, were aww-inducing  while running errands in LA on Monday.