When a serious or heartfelt moment is undercut by something absurd or
nonsensical.
This is a reference to a scene in the
video game YIIK: A Postmodern RPG. When the character Rory is bearing his soul about his deceased sister, and Vella is sympathizing with Rory's grief. The
emotional scene is interrupted by a Golden Alpaca who keeps saying Lemonade, with goofy background music playing as you're thrown into combat against them.
My brother Kevin had a hell of a Golden-Alpaca Moment at
the wedding. He shat himself
directly into the sky when it was his turn to say "I Do."
I'm still
cleaning the feces out of my tuxedo.