Green’s Dictionary of Slang

1. to do, say or wear something surprising or exciting.

1989

P. Munro Sl. U. 45: Look at Shelly, she’s trying to break out with her new outfit.

2. to produce something unexpected and/or suddenly.

1989

P. Munro Sl. U. 45: Everyone at the party was bummed out because there was no more beer. Then Lauren broke out with a six-pack.