Watch EW’s exclusive sneak peek of the How I Met Your Mother character’s reappearance below.
“I broke 100 times,” Duff tells EW with a laugh.
I don’t know how we can’t tell on camera.'

Neil Patrick Harris and Hilary Duff on ‘How I Met Your Father’.Patrick Wymore/Hulu
It was so funny.
But he’s just the best sport, and it was a dream to have him on."
Harris credits originalHIMYMdirector Pam Fryman with making sure everything turned out okay.

Patrick Wymore/Hulu
All of it felt surreal, and exciting, and also business as usual.
I loved to be a part of it."
And it turns out that Smulders reprising her role is what set Harris' return in motion.
“I knew that Cobie got to play Robin in season 1 of the show,” Harris says.
“And I thought, ‘Oh boy.
Well, now this is inevitable.
They’re going to ask all of us.’
Once Cobie does something, how can you say no?
Everyone loves Cobie Smulders and she did a great job, and it was wonderful.
And thankfully Pam had reached out.”
Harris agrees immediately, “Exactly, I don’t doubt that’s the case.”
But he notes that he didn’t want to appear on the show simply for nostalgia’s sake.
“In what direction do you want him to have aged?
Is he worse, is he better, is he different, is he the same?
What they had come up with was a smart call.
But Duff admits that her nerves kept getting the better of her.
I couldn’t remember any of my lines after that.
It was a very exciting moment.
Harris laughs as he remembers those first few takes.
“So it’s nice, the yin and the yang of it all.
We got there.”
How I Met Your Father’s two-episode midseason finale debuts Tuesday, March 28 on Hulu.
Season 2 returns Tuesday, May 23.