Bro
A guy who talks and acts like a regular straight dude, cap, beer and sports included; on the apps, a code for masculine, low-drama and often discreet.

In gay slang a bro is a guy who talks, dresses and acts like a regular straight dude: baseball cap, gym shorts, beer, sports on the TV, "dude" in every sentence. Some bros are straight, some are gay, many are somewhere in between and would rather not discuss it. What matters is the vibe, which is casual, laddish and allergic to anything that looks too gay.
For a lot of gay men the bro is a fantasy, for others a type to avoid, and for some a costume they wear on the apps. The word sits between masc, jock and str8, and it carries a bit of each.
Where it comes from
Bro is short for brother and very old: Green's Dictionary of Slang finds it in 1762. As a way of addressing a friend it grew up in African American speech in the 20th century, recorded from the 1920s. The bro as a type, the loud, athletic, partying frat boy, is campus slang from fraternity brother, and it is much more recent; Green's first clear example is a university slang survey of 2011. Around it grew a whole family, from the bro code, the unwritten rules between guys, to bro up, to make friends.
Bros on the apps and in porn
On Grindr and friends, "bro" is a code. A profile that says "just a chill bro looking for another bro" is telling you: no camp, no drama, maybe no kissing, and possibly not out. It overlaps with DL and discreet, and with the whole masc-for-masc culture that many gay men find hot and many find tiresome, especially when it comes with "no fems" in the bio.
Porn turned it into a genre. Bro scenes play with the idea of two "straight" buddies who end up helping each other out: the video game, the shared couch, the "it's not gay if...". It is a close cousin of frat porn and straight bait, and it gave us bro job, a blowjob between buddies who insist they are only buddies.
Bro or jock
A jock plays sports and has the body to show for it. A bro may never have touched a ball since college; he just talks like he did. A jock is about the gym, a bro is about the attitude. And a himbo is a bro who is too nice to pretend to be straight.
Plenty of gay men call their friends bro with no irony at all, the same way they call them babe or sis. Context does the rest.
Related terms
Sources 1
- Green, Jonathon. "bro, n.1." Green's Dictionary of Slang, online edition. https://greensdictofslang.com/entry/b4e3mey