DANIEL RADCLIFFE is reportedly dating ERIN DARKE, his co-star in a new movie called "Kill Your Darlings".  The two of them were spotted kissing and "cuddling" at the Sundance Film Festival.  (Here's a picture of her.)

On a related note, Daniel has GAY SEX SCENES in the movie.  And he's surprised that people think it's such a big deal.  He says,  "For me, there's something very strange about that because we see straight sex scenes all the time.  We've seen gay sex scenes before.  And I don't know why a gay sex scene should be any more shocking than a straight sex scene.  Or both of them are equally un-shocking."