Can you call an adult bruh?

You can if you know them well and you know they wouldn't mind. Otherwise it is disrespectful. Same with calling an adult, dude.

not at all in my opinion

WHAT DOES BRUH MEAN?

you shouldn't , it's childish

Why you so mad bruh?  It's online.  

You talk to "In Real Life"(old) people the same way you talk to online people.......you may find a line of IRL people pissed at you.

Personally, if you had a Californian accent, id say go for it even with older people.  You make it work!

It is only disrespectful if they're the type of person who says Bruh, as obviously you're trying to do this ironically.

Why would you? Only a jackass calls somebody bruh.

You can, but it sounds immature outside of a casual environment.

not if they dont like it