Martin Henderson gushes over ‘down to earth’ Britney Spears in a new interview with ET’s Katie Krause. The actor recalls what it was like working with and kissing Britney in her ‘Toxic’ music video 15 years ago. Martin also reveals if he would be up for a ‘Grey’s Anatomy’ return as doctor Nathan Riggs. Season two of his hit Netflix show, ‘Virgin River,’ is now streaming.