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We're with Neil Patrick Harris, Cobie Smulders and Josh Radnor on the set of How I Met Your Mother to get the skinny on the eighth season premiere episode – and what they think about how this could possibly be the final season of the CBS hit!

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"We're such a family," Neil tells ET. "It's a remarkably happy environment, so if the season ends at eight, it would be hard to find a future job that equaled this one in pure happiness, I think." Josh adds, "The show's been going on for a really long time and I think all of us feel really blessed by that," while Cobie says, "When I think about it, I want to cry. ... it'll be very strange. My hope is we can do more."

In the season premiere, airing Monday, September 24, Robin (Smulders) suffers from anxiety on her wedding day to Barney (Harris) and gets help from Ted (Radnor) to calm her jitters.

"I think Barney's a one woman type of guy, just in sequence -- you know, one woman at a time. Although he's been a four or five woman guy before, so let's hope that Robin is into key parties," laughs Neil.

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Watch ET for more with the cast of How I Met Your Mother!