My memory is a little fuzzy, but does anyone remember this Nick interstitial series that would air from 2013 to 2014? I think it was about a normal stock video compared to a Nick clip. I remember seeing a Sam & Cat version where Sam would say something like "Do you feel like dancing?" to Cat and would proceed to dance. Dice then says that the song they are dancing to will make them explode, and Sam says something like "We are not going-" and, mid-sentence, both Sam and Cat explode. The funniest thing is, the clip isn't even a part of an episode, and I think it was only used for that interstitial but was edited to make it feel like it was a clip from the show.
As someone who watched Nick around that time, I know exactly what you're talking about. It was part of an interstitial series called "Nickelodeon Funny Rules" where they spliced clips from their sitcoms focusing on specific types of comedy. You are right that it wasn't from an episode...technically. A short snippet was used in one of the many montages in the blooper clip show, but that was it. And it seems that nearly all of the interstitials have been archived, except this one.