OK! EXCLUSIVE: Ashley Greene & Joe Jonas — London Love Fest!

He may have walked the red carpet with Nikki Reed at the Eclipse UK premiere, but Joe Jonas is getting cozy with another on-screen vampire — Ashley Greene! The hot young Hollywood duo have been spotted out together in London, a source tells OK! exclusively.

OK! GALLERY: JOE JONAS GIVES FREE HUGS FOR FANS & GRANDPARENTS

"Ashley brought Joe to the Kings of Leon concert in London, and there was definitely something going on, but it's not serious," a source tells OK!. "They went backstage and she was talking to the band a lot, and he was just hanging out."

While there may be only some sparks flying between the pair, Joe, 20, seems very into Ashley, 23.

OK! GALLERY: ASHLEY GREENE SOAKS UP THE CITY SUN

"I think he wants it to be more than she does right now," the source adds. "She's a maneater."

A rep for Ashley told OK!, "they're friends".