When two males acknowledge having been intimate with the same female and remain on good terms, the men are now bonded by having shared the same igloo at one time or another.
This can lead to perks by making the information known to other males who you can network with.
Male 1: "Yea man, I got us a hook up at the show tonight, we don't have to pay cover"
Derived from a show called "The League". This was introduced by actor/comedian Jon Lajoie
"Dude, I had sex with Cindy last night!"
"Oh yeah... that's cool. I fucked her 2 weeks ago. That means we're Eskimo Brothers"
"What? We've been going out for months..."
OR
"Hey bartender, let me get a free drink. We're eskimo brothers!"