In what is easily the worst news we’ve heard this week, Us Weekly reported Thursday that Burlington’s own Amy Poehler and husband Will Arnett are separating after nine years. “It’s very amicable,’’ a source told the magazine. The couple’s rep confirmed the separation. The pair have two sons, Archie, 3, and Abel, 2. Poehler, 40, is best known for her work on “Saturday Night Live’’ while Arnett, 42, appeared on the sitcom “Arrested Development’’ and in several films. He was previously married to actress Penelope Ann Miller for one year.