SHEFFIELD, ENGLAND -- On Saturday night (Oct. 31), One Direction threw a spook-tacular (get it?) end-of-tour party in Sheffield, England at their last On The Road Again stop of 2015. Fans were very emotional, and so were all eight dudes onstage -- including the awesome 1D live band.

Of course, there were tears. But there were far, far more smiles from the moment Directioners began lining up outside the arena to the last fleeting seconds of grand finale "Drag Me Down."

The best grins -- you know, the shiniest -- came from Harry, Louis, Niall and Liam when, near the end of "Act My Age," Liam's dad suddenly flew down the aisle near the runway with an entire conga line behind him. Yeah. It was strange and entirely unexpected and awesome.

That's none other than Geoff Payne himself at the front of the dancing queue, wiggling his way right up to where the boys could see and, fittingly, lose their sh-t.

Liam was incredulous. "Honestly, I never thought I'd see the day my dad would lead the conga down the aisle," he told the crowd. To commemorate such an occurrence, there was only one thing to do: repeat the cool little Irish jig part of "Act My Age" again and again to keep everyone jumping.

So that's what they did. Several times.

You can watch the hilarious full video below and use it as a guide to assembling your own conga line next time you listen to Four -- or even better, when Made In The A.M. drops on Nov. 13.