Man, 'Alvin and the Chipmunks: Chipwrecked' was such a fun ride, but Brittany's frustration with Alvin? Totally justified. See, Alvin's always the reckless one, charging ahead without thinking, and in this movie, he literally gets them stranded on an island after his antics cause their cruise ship to sail away without them. Brittany's the practical one—she cares about safety, appearances, and keeping things together. Alvin's impulsiveness ruins her plans, and worse, he doesn’t even seem sorry at first.
What really seals it is how he keeps dragging the others into his schemes, like when he tries to 'explore' the island and nearly gets everyone eaten by a snake. Brittany’s justifiably furious because his behavior puts them all in danger, and she’s stuck cleaning up his messes. Plus, let’s not forget her competitive streak—Alvin’s chaos undermines her efforts to keep the group looking good, especially when they’re supposed to be performing. By the end, though, she softens when Alvin finally steps up, but for most of the movie? Yeah, she’s got every right to be mad.