Martin Henderson may not have a romantic plot line on Grey's Anatomy yet, but there's one steamy role he's still holding on to: starring opposite Britney Spears in her "Toxic" video! 

"It was a legendary kiss!" He tells Us Weekly of his sexy scene with the 34-year-old singer. "It was certainly a nice day at the office."

While Henderson, 41, wouldn't confirm or deny taking their hookup off screen, he tells Us that the two did attempt to see each other after filming wrapped."We communicated a couple of times," he says. "I was actually trying to meet up with her somewhere to see her perform, but then I had a job and it never happened. Then we just lost touch."

Though Spears was one of the biggest names in pop music at the time of the video's 2003 release, it wasn't her fame that the New Zealand native was attracted to. "She was so down to earth, and I remember really being charmed by the way she made fun of her own song," he says. "In between the set-ups that we were filming, she was miming her own music and kind of making fun of herself. I thought that was a really healthy way to be."

Although Henderson, who dated Demi Moore in 2012, has moved on to playing the hunky Dr. Nathan Riggs on the ABC hit (returning Thursday, February 11, at 8 P.M. EST), he plans on re watching the music video for years to come. "I'll be showing my grandchildren that video," he says. "When I'm all old and wrinkly and they're looking at me like a sad sack, I'll be like, 'Well, your granddaddy used to make out with Britney Spears!'"

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