helped celebrate Robert Pattinson
's twenty-sixth birthday Sunday evening, May 13th
. Several other celebrities - including Les Mis
producer Cameron Mackintosh (pictured with Hugh) and Sienna Miller
- were in attendance at the dinner at Claridge's in London, England. Hugh has met Pattinson before, when the two of them sang karaoke in Japan several years ago. They're also rumored to co-star in ...