Lady Gaga and Taylor Kinney: Dating?

By Jessica Herndon

09/09/2011 at 09:30 AM EDT

Could a fresh romance be blossoming between Lady Gaga and CW star Taylor Kinney?

Kinney, who stars on the series The Vampire Diaries, also played Gaga's mad scientist love interest in her "You and I" video.

A source tells PEOPLE that Gaga, 25, and Kinney, 30, who met on the video shoot back in July, are "hooking up."

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The two were reportedly spotted in the Mission Viejo, Calif. over Labor Day weekend and a source close to Gaga confirms that the pair "were hanging out" over the holiday.

Gaga was last linked to musician, bartender and fellow New York native Luc Carl, whom she dated off and on for a few years. In July, a source told PEOPLE that Gaga and Carl were once again going strong and that she wrote "You and I" about their rekindling.

•With reporting by CARLOS GREER and JESSICA WEDEMEYER