By Niamh Spence Kim Kardashian has delighted fans as she revealed a new SKIMS campaign with singer Usher modelling the label’s underwear base layers. The campaign comes ahead of Usher performing the half time show at the NFL Super Bowl on Sunday, where the singer has said it’s “an honour of a lifetime” to finally perform at the iconic sporting event. His 13-minute show has been long awaited by fans, and is expected to be a key highlight of the game. Ahead of his performance, Kim Kardashian has snapped up the musician to model for her label SKIMS with the singer stripping down to his underwear …