Lollapalooza Argentina went down this past weekend, and we’re just now getting our first reports of rock-star hijinks. Arcade Fire experienced their second heinous act of heinous bobblehead thievery, as Strokes frontman Julian Casablancas (who didn’t exactly impress in his own Lolla Chile set during the same weekend) interrupted the beginning of Arcade Fire’s set while wearing Win Butler’s gigantic paper-mache mask. Butler quickly kicked him offstage, and it’s obvious from everyone’s goofy grins that this was an all-in-good-fun friendly prank or (more likely) a planned stunt. Still, it would be pretty funny if this turned out to be the first shot in a war of the frontmen, and if Butler started showing up at Casablancas solo shows and screaming for “Last Nite.” Watch the sheepish stage invasion below.

Honestly, though, if you’re touring around with enormous hideous masks, you’re just asking for this sort of thing.