Long before he found fame as Dean Winchester in “Supernatural”, Jensen Ackles caught his big break when he was cast on “Dark Angel”, the James Cameron-produced series starring Jessica Alba as a genetically enhanced super-soldier.

During a recent appearance on the “Inside of You” podcast, hosted by former “Smallville” star Michael Rosenbaum (via TooFab), Ackles revealed that working with Alba was a somewhat fraught experience.

Asked by Rosenbaum if Alba was “cool to work with” on the show, Ackles replied, “No, she was horrible.”

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He also insisted that he wasn’t joking, and had “told this to her face.”

Of course, Ackles was also quick to point out that Alba was “under an immense amount of pressure,” given she was just 19 when she was cast as the lead on “Dark Angel”, and then became scrutinized by the tabloids due to her “rocky” relationship with co-star Michael Weatherly, 12 years her senior, all of which was “causing some undue stress on set.”

Ackles joined the show in its second season.

“I was the new kid on the block and I got picked on by the lead,” he said. “Like, the worst kind of bickering a brother and sister could do. She had it out for me. It wasn’t that she didn’t like me. She was like, ‘Oh, here’s the pretty boy the network brought in for more window dressing because that’s what we need.'”

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Ackles, however, fought “fire with fire,” admitting he ribbed Alba back just as much.

“So I was just like, ‘Oh, looks like we’re getting b***h Alba today, everybody hang onto your nuts,'” he recalled, noting the crew “loved it” when he stood up to her — even though it made her feel, “Okay, now I can just be a d**k to him and he’ll be a d**k to me and that’s how we’ll roll.”

Eventually, however, that back-and-forth “did build some mutual respect” between them.

In fact, Ackles also praised Alba for being there for him when his grandfather died.

“She literally walked into my trailer and just held me for half an hour,” he recalled, noting that they took to hanging out together in a “very platonic, very brother-sister” way when Weatherly was out of town.

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“So it was that kind of relationship,” he said, “but she didn’t make it easy on me.”