I've never done it, I get what you mean. Like 2 guys in my year do it and it's I just find it a weird thing to do here straight or whatever. 'Bro' and 'Bruh' isn't a thing here either so when people use it and not ironically its...
In 9th grade there was a special handshake the straight guys at my school were doing. One day the guy I had a crush on put his hand out to shake mine and I couldn't tell if he was just looking for a regular handshake or the special handshake. I did like a combination of both and it was really embarrassing.
I guess handshakes aren't a thing in the US In Spain/Latino America men do it all the time, that's how we greet another man Usually gay men kiss each other on the cheek though