Sweat of bros
When you get a lot of bros in one place. While many people may seek to avoid this many bros, others will head straight into the maelstrom of flat-caps, khakis and Topsiders.
"Yo girl, It's St. Patricks Day and there are a sweat of bros in that bar." "Well I was going to pledge for that frat but I realized there was already a sweat of bros in there. Perhaps I will try knitting club."