Not a cool story.
(And not necessarily towards your/a "Bro".)
Girl 1: I went the to mall today and...
Girl 2: Cool story bro.
A sarcastic way of acting like you give a shit of what the other person has to say. Usually this phrase best pertains to Facebook updates and mundane stories with pretty much no point or purpose.
-Bob: Frosted Flakes are bomb, dude!
-Joe: Cool story, bro!
---
Facebook update:
-John is going to get a bananna at the store
-You: Cool story, bro!
4chan saying commonly used when sayer is listening to someone talk to him and doesn't really care
1. so this one time we were sledding down a hill and we totally got broke
2. Cool Story Bro
Used to defend against an impending cool story bro. Usually uttered immediately after the narration of a story or anecdote (for full effect) worth telling, relevant to the conversation, and not an example of tl;dr or faggotry, so that any threat of ownage from jackasses is effectively neutralized. (Often abbreviated as' tsb' when used in text)
Person A: I remember I was stuck in an elevator in freshman year with a claustrophobic chick who was panting the shit out of the elevator. Gave me the heeby jeebies. True story bro.
Person B: ...
A way of saying "I don't care what you're saying but I'm gonna go ahead and say I liked the story."
Usually used after listening to a long story or gossip.
A phrase used to express indifference or boredom to a long or boring conversation.
There are many different types of "cool story bro". There is:
1) cool story bro
2) cool story bro, you should write a book about it
3) cool story bro, in which chapter do you shut the f*ck up?
etc.
1) Chad: I ate an apple for breakfast
Angie: Cool story bro.
2) Hannah: And then I rinsed my teeth. And then, lo and behold, I saw a black mark. I thought: "Hmm, what can it be?" and hark! It was a cavity! So then, I --
Josie: Cool story bro, you should write a book about it.
3) Tad: boring and lengthy story about scientists growing a new type of capsicum
Beth: Cool story bro, in which chapter do you shut the f*ck up?
When someone tells you something and you simply don't care.
Person 1: Man, I don't feel like living anymore. My grandpa died yesterday.
Person 2: Cool story bro.