HBO exec James Costos officially has a new title — ambassador to Spain and Andorra. Costos was sworn in late last week in Washington, DC, by Under Secretary of State Patrick Kennedy. The ceremony was witnessed by 75 friends and colleagues from New York, Los Angeles and London — but most notably his partner, Michael Smith, who is the First Family’s interior designer of choice for the private quarters of the White House. Costos is the vice president of global licensing and retail, consumer marketing for HBO. He and Smith have raised at least $500,000 for President Obama’s reelection by hosting fund-raisers in their plush New York apartment. Friends at the swearing-in also included Wallis Annenberg, Architectural Digest editrix Margaret Russell, Net-a-Porter founder Natalie Massenet, Ford Motors heir Alessandro Ford Uzielli and Ebony’s Linda Johnston Rice. Guests enjoyed a Spanish feast before the ceremony at José Andrés’ Jaleo. Look out for a made-over Madrid embassy in the manner Smith did the Oval Office.