According to Jensen Ackles, his early days on Dark Angel were not-so-heavenly. During his appearance on the Jan. 18 episode of Inside of You: Michael Rosenbaum, the Supernatural alum admitted that he and Jessica Alba didn't exactly click right off the bat while co-starring in the science fiction drama. Calling his experience "horrible," Jensen added, "I'm not kidding. I've told this to her face." However, the actor clarified that looking back now, he can understand the circumstances. "I love Jess, which I know kind of contradicts what I've just said," he added. "She was under an immense amount of pressure on that show. She was young and was in a relationship [with co-star Michael Weatherly] and that was causing some undue stress I believe." Jessica was 19 years old when she landed the role on the FOX show. Jensen officially joined the series in season two, to which he attributes for some of the tension. Jensen then explained, he learned to "fight fire with fire," which eventually led to "mutual respect" between the pair.