Man, someone drank the last of my blueberry muffins.
Want a PBR? Nah, I have blueberry muffins.
When a bro is intoxicated and chatting-up a girl (one of exceptionally bad quality), it is ANOTHER bros responsibility to warn his bro of the bad decision he is about to make.
In this situation the term "blueberry muffins" is subtly used as code for "Get the fuck out of there! ABORT ABORT!".
person 2: Did you get a Blueberry muffin at the end?
person 1: Yeah, it cost me an extra $20.