Kate Hudson and Derek Hough are continuing to keep their fans guessing about their romantic status.

The 36-year-old Almost Famous actress and the 30-year-old Dancing With the Stars pro first sparked dating rumors last December, when they were reportedly hooking up after Kate called off her engagement to Muse frontman Matt Bellamy. On Tuesday night, the attractive blondes were spotted in a warm embrace at the U2 concert in Los Angeles.

WATCH: Is Kate Hudson Dating Derek Hough After Calling Off Engagement?!

Kate and Derek appeared to be on a double date with Julianne Hough and her boyfriend, NFL player Brooks Laich. Derek, however, was apparently feeling camera shy that night -- the rumored couple started to hug when the four of them left the concert together, an eyewitness tells ET, but as soon as the dancing star noticed the photogs, he "practically ran away."

"They were definitely on a date," the eyewitness says. "They came out in a crowd of people and looked really relaxed and happy."

A concertgoer was able to snap a photo of Kate and Derek inside the venue, but they didn't appear to be overly affectionate.

Meanwhile, producer/director Heather Parry Instagrammed a photo of her and Julianne and Kate together Tuesday night, writing, "My favorite band since high school. #U2 ? @katehudson @juleshough."

PHOTOS: Kate Hudson Shows Off Her Insane Body in Skin-Bearing Versace

Kate's ex Matt has clearly moved on from their four-year relationship. He and his new girlfriend, model Elle Evans -- who you'll probably remember from her appearance in Robin Thicke and Pharrell's "Blurred Lines" video -- recently made their red carpet debut as a couple at amfAR's 22nd Cinema Against AIDS Gala in Cannes, France.

Watch below: