From the Reliable Source (with no indication that a White House waiver will be required):

Engaged: Melody Barnes, 44, and Marland Buckner, 42. She’s a senior domestic policy adviser at the White House; he’s a Democratic staffer-turned-lobbyist. The two met 10 years ago (she was Ted Kennedy’s chief counsel; he worked for Chuck Schumer and Harold Ford) and started dating 18 months ago. June wedding in Washington; first marriage for her, second for him.