After being hospitalized for “dehydration” last month, rapper Lil Wayne was back in action Sunday. Spies saw the Grammy winner having a boys’ night out, with Fat Joe and Sean Kingston, to celebrate rapper French Montana’s 28th birthday at Miami Beach club Bamboo. “He surprised everyone by showing up,” said a spy, and, “He had a blast.” Outfitted in a cap and shirt blaring his clothing line TrukFit’s logo, Wayne and pals partied till the wee hours, ordering Ciroc vodka and Patron tequila.