Amanda Seyfried and Justin Long stepped out for a rare public appearance at the Costume Institute Gala at the Metropolitan Museum of Art in NYC on Monday night. Amanda, who wore a white Givenchy gown, was all smiles while posing for photos with Justin on the red carpet. The extravagant event is a far cry from the couple's normal routine. Amanda and Justin, who started dating nearly two years ago, are normally seen being goofy with each other during casual outings.??