Hilary Duff Says She Was ‘Nervous’ Filming Neil Patrick Harris Cameo for ‘How I Met Your Father’: ‘It Was a Big Deal’ (Video)

“They only handed out certain scripts with his scene in it,” Duff tells TheWrap

Hilary Duff admitted she was nervous to meet “How I Met Your Mother” royalty Neil Patrick Harris during his recent “How I Met Your Father” cameo, noting that his appearance was “such a big deal” that it was kept under wraps with many unaware he was even coming to set.

“Him coming on to the set was a such a big deal that they only handed out certain scripts with his scene in it, and the other ones [had] missing pages or just didn’t make sense in the context of like, going from this to that,” Duff told TheWrap. “It was a big, big, big, big deal – and I felt very nervous and excited.”

Despite her nerves, Duff gushed that the “How I Met Your Mother” actor was “everything that you would think he would be,” emphasizing that he was “really freaking cool.”

“[He was] handsome and charismatic and smart and witty and on it and weirdly human at the same time,” she said.

Harris returns in the Hulu series mid-season finale as as Barney, an unassuming driver who Sophie (Duff) rear-ends amid the looming concern that she might be dating her father after realizing her boyfriend (John Corbett) attended the same music festival where she was conceived. Once Sophie and Barney get out of their cars following the crash, instead of being angry, Barney begins reciting a prewritten apology for being a “serial womanizer” in recovery.

“My name is Barney Simpson and I am a recovering serial womanizer,” Barney says as he reads from his list. “We are likely speaking today because you are a woman I once concocted an elaborate scheme to have sex with. I fully understand why you’ve exacted revenge on me and I apologize if I ever a) pretended to be a mannequin that came to life and made you fall in love with me” – and so on and so forth.

After making a lewd comment in reference to Sophie’s body, Barney experiences a painful shock from his STD (shock therapy device), which is designed to deliver a blow should he say one of the 10,000 words or phrases it has programmed as problematic language. 

“I really love what they did with his storyline,” Duff said. “They kind of showed that there’s been growth in him as a person since how you’ve seen him last on ‘How I Met Your Mother.’”

After recalling her estranged relationship with her father and her twisted epiphany to Barney, he encourages her to pursue a relationship with her dad, meanwhile letting her off the hook for the fairly considerable damages to his car.

“He gives Sophie this really incredible gift that kind of pushes her out of her comfort zone to go and meet her her father,” Duff said.

“How I Met Your Father” is streaming on Hulu, with the mid-season finale premiering Monday.