Alright guys, amuse me.....

IF:

I like a girl: I'll remember not to introduce her to my friends.

I really like a girl: My friends probably still won't know her. Safe distance.

My girlfriend: hands off?

My Ex-Girlfriend: Fair game. Why let her go to waste?

if I liked a girl I wouldn't expect my boys to back off cause there's a chance she might not even like me lol.

No such thing as really like to me, its either "like" or "g.f"

If she was my girlfriend I'd love to think my boys would consider her as untouchable but there's a lot of dumbass dudes out there that will f*ck around no matter what.

My ex, I don't care what happens cause I don't pay attention to ex's. It creates too much baggage if you sit and think about all of it.

Your wording is kind of confusing but I think I know what you're asking. You want to know about the notorious "bro code" or guy code as you call it. Well if any guy friends are around the girl they know you are interested in then they will stay at somewhat of a distance from the girl as to not try and attract her away from you. Other random guys may take this as an opportunity to challenge you and try to bag the girl themselves. It really depends on how well you know the other guys and how much they know about you liking the girl.

If I liked a girl a bit, I'd probably just observe her around her friends for awhile.
If really like a girl, I would try to start a conversation with her and be her friend before ever asking her out. I'd she if she flirted with me.
If she was my girlfriend, I would try to make her feel special and do what both of us wanted.
If she was my ex-girlfriend, then it would depend entirely on the intensity of the relationship.