Girl Code? Does it exist?

So, I've become fascinated with the term girl code. Is their such a thing? A few days ago, a few of my friends and I had a girls night. This girls night included food (of course) and talking about heartbreaks, lovers, and potential lovers and then of course makeup and hair and all of the stuff that makes us girls. blah blah blah. 

Well during our wonderful discussion we came upon a name. A boys name, of course. Woah, Nelly. The drama started up. This girl told us of this boy who dated her for 3 months- told her he loved her- wanted to marry her and when he got presented with a amazing chance to travel he took it. He didn't tell her, didn't say what was going to happen with them and left with no explanation.

Naturally, the girls heart was shattered.

As she was relaying this story, one of the other girls at the table  said " Oh. That sucks, I'm sorry. He told me that it just wasn't working out with you two- and that he just wasn't feeling it anymore." "Oh, and do you want me to say anything to him for you?"

Then all of the sudden Hell broke loose.. 

And it got really really awkward.

To say the least, the rest of the night was a tad uncomfortable.

Which made me ask my question  "Should girlfriends even talk to their girlfriends ex's? Should they be friends with them? " or is their a girl code that says no? What about dating them? Or... getting married to them? Ha ha. 

But seriously.

Boys have their Man Law, and though they are silly- they stick next to them like no other. For instance, If you've known a guy for more than 24 hours, his sister is off

limits forever unless you actually marry her. Or the one that says you can't talk to another man in the bathroom. But most importantly, boys don't date another boys's ex- especially if they were in love with that girl.

So the question still resides. What's appropriate? I need feedback. 

Until later. -Amanda.