Credit: Jeff Kravitz/FilmMagic

They've long played coy on rumors of a romance, but Alexander Skarsgard has nothing but good things to say about his Straw Dogs costar Kate Bosworth.

"She's amazing," the True Blood actor, 33, tells Extra of his costar in the upcoming remake of Sam Peckinpah's classic thriller. "It's been a couple of tough weeks [of filming] now, and she's been amazing."

The pair first raised eyebrows when they were spotted cozying up at October's Spike TV Scream Awards in L.A. They even shared a quick on-stage smooch when Bosworth, 27, presented Skarsgard with the Best Villain award.

"Kate and Alexander hugged a few times and were often spotted whispering to each other," reported of the pair's backstage rapport. She even "playfully slapped him on his butt a few times," according to the site.

Still, Bosworth herself insists she maintains a purely platonic relationship with True Blood's vampire baddie.

Spotted at a showing of Fantastic Mr. Fox a month after the Scream Awards, the couple kept their distance.

Asked about their relationship status, Bosworth told paparazzi photographers "Friends, guys!" as she jokingly punched Skarsgard in the arm. "We work together."