Rapper Kanye West gushed about his pregnant girlfriend Kim Kardashian on Monday night (06May13) as he debuted a new track inspired by the reality TV star at the Costume Institute Gala in New York. The Stronger hitmaker hit the stage at the Metropolitan Museum of Art event, also known as the Met Ball, and premiered his latest song for celebrity guests including Beyonce, Gwyneth Paltrow, Blake Lively, Sarah Jessica Parker, Uma Thurman and Anne Hathaway. A source tells UsMagazine.com, "(The song was) an ode to Kim... about how awesome she is. The audience was jamming to it. Kim was smiling and loving it." Supermodel Coco Rocha also shared a clip of West's performance with her Twitter.com fans and explained in the accompanying caption, "Kanye telling Kim not to worry what anyone says that she's awesome (sic). Quite touching really." West and Kardashian are expecting their first child together this summer (13).