Two migrant teens were busted for swiping thousands of dollars in designer duds from a downtown Brooklyn Macy’s late Wednesday, law enforcement sources said. Alan Bello, 18, and a 17-year-old boy whose name has not been released scooped up a stash of name-brand clothing during the heist at the Fulton Street department store just after 9 p.m., cops said. They tried to leave with the stolen goods – worth about $2,421 – before a worker stopped them in their tracks, police and sources said. Cops responded and arrested both teens on the scene, charging them with grand larceny, police said. They are known to be migrants, sources said, though their country of origin was not immediately known.It was also unclear whether the pair had been previously arrested in the Big Apple.In a similar case this past spring, Venezuelan migrant Brian Castillos, 22, was nabbed for trying to steal $299 in goods from the same Macy’s, according to that criminal complaint.He has also been busted this year for allegedly using a stolen credit card at a Manhattan NBA store, and snatching a woman’s necklace in a Hell’s Kitchen sidewalk heist, according to those complaints....