The singer enjoys an evening out in London. Plus: Eva Longoria, Katy Perry, George Clooney, Taylor Kitsch and more

FANTASTIC FOUR

Colin Firth and wife Livia mingle with Emily Blunt and John Krasinski while hosting a Ermenegildo Zegna and Vanity Fair benefit dinner – in support of Oxfam America and Livia's eco-friendly initiative the Green Carpet Challenge – at L.A.'s Chateau Marmont on Wednesday.