This Week's Can't-Miss Shots!

Some of our favorite stars gave us pretty contagious smiles this week, setting the tone for a happy Spring. Kate Middleton broke out in giggles when she spoke with Irish Guards at a St. Patrick's Day event, and Scarlett Johansson lit up when she and Chris Evans brought their Captain America premiere parade to London. Meanwhile, Ryan Reynolds made our hearts stop with his smoldering stare and semipopped collar, and Charlize Theron had us wondering when her bikini photo shoot snaps will be released. Keep reading to see all that and more! Source: Getty and FameFlynet

FameFlynet

Charlize Theron struck sexy poses throughout her bikini photo shoot in Key West, FL.

Getty | Pool

Michelle Obama had a blast playing ping-pong on Thursday during her action-packed stay in Beijing.

Getty | Ben Gabbe

Shailene Woodley and Theo James shared a sweet moment at Thursday's screening of Divergent at NYC's Hearst Tower.

Getty | Samir Hussein

Scarlett Johansson walked the red carpet with Chris Evans at the UK premiere of Captain America: The Winter Soldier in London on Thursday.

FameFlynet

On Tuesday, Ryan Reynolds paid a visit to the set of The Age of Adaline in Vancouver, where his wife, Blake Lively, has been filming her latest project.

Getty | WPA Pool

Kate Middleton had a good laugh as she participated in an annual St. Patrick's Day tradition of visiting the Irish Guards in Aldershot, England, on Monday.