Most Helpful Guy
Well, it is not written in stone, y'know. There are unwritten rules that govern human behavior in general. Close friends (or bros) have those as well, but it is different from one group to another. Some friends like to bang a girl together on the same bed, others live and die not seeing (or wanting to to see) their best friend naked.
So, yeah, I just follow common sense and try my best to avoid the things that may upset my "bros".