The actress Emily Perkins, who plays Becki Rosen in Supernatural, did an interview to Examiner.com and quote Jensen on it.
Jared and Jensen are the kind of guys that could bring out anyone’s inner love-sick maniac, and in person even more so. I was extremely nervous to work with them; I even had my lines written down on a tiny piece of paper in my pocket in case I forgot them. But Jared and Jensen were so easy-going, professional and friendly, that I was soon able to relax and just enjoy the experience.