Crystal Hefner hosts and DJs at the 2015 Rehab Bikini Invitational at Rehab on Saturday, June 13, 2015, in the Hard Rock Hotel Las Vegas. Crystal Hefner, minus husband Playboy mogul Hugh Hefner, played hostess with the mostess – and in her skin-tight dress, she really had the mostess – and DJ at the 2015 Rehab Bikini Invitational at Rehab on Saturday afternoon in the Hard Rock Hotel Las Vegas.