How I Met Your Mother star Neil Patrick Harris says one particular cast member had a hard time nailing the show’s 100th episode musical number choreography. The popular sitcom ran for nine seasons between 2005 and 2014 and featured an ensemble cast that included Harris, Jason Segel, Alyson Hannigan, Cobie Smulders, and Josh Radnor. Harris played lovably immature womanizer Barney, whose storylines frequently involved women he is sleeping with or trying to sleep with.

In the 100th episode of the series, creators Craig Thomas and Carter Bays had a little more room to experiment. Since the two were also in a band together, they enjoyed incorporating music into HIMYM episodes whenever possible. Elsewhere, this was shown through the Robin Sparkles storyline which featured Smulders’ character as a Canadian teen pop sensation and in the memorable slap bet song sung by Marshall, “You Just Got Slapped.” But for the 100th episode, the HIMYM team decided to go all out with an impressive ensemble musical number titled “Nothing Suits Me Like a Suit.”

In a video with Vanity Fair, Harris talked in-depth about HIMYM’s 100th episode, his favorite from the show’s run. With Harris’ theater background, it was exciting for him to be able to flex his vocal and physical talents, but not all his co-stars were as suited to that sort of performance. Harris amusingly reveals who had the most trouble with the choreography below:

• It was a hot day, and we all had to do kick-lines together, and some of the cast was struggling more with all of the specifics of the choreography more than others (coughs) Jason Segel, and so that was sort of fun to watch, we’d have to do that multiple times so people would understand it, but it was all happening very quickly.

Harris’ comments are fitting considering some of Barney’s digs at Segel’s character Marshall during HIMYM’s run involved his awkward physical proportions and clumsiness. Those jokes seem to have stemmed from a real place considering Harris’ indication that Segel is not much of a dancer. The actor’s words about the trials the full cast and crew went through in order to put the scene together certainly stand as a testament to their dedication to pulling off the spectacular sequence. Though it was hard work for many, their efforts paid off, and the dance number stands as one of the show’s most memorable moments.

While Marshall and Barney shared a friendly rivalry at times and Harris lightly teased his co-star with his comments on the dancing, Segel and Harris created and maintained a close bond on the series. They weren’t alone, with many HIMYM co-stars mentioning over the years the fun times they had while filming and even saying they’d be open to reprising their roles. Smulders has already done so as Robin in a cameo in the spinoff How I Met Your Father. With the affection the rest of the cast clearly have for one another, perhaps more appearances will follow.