Guys (most guys) have a few Unwritten Rules that they follow. Like never ever date a guy's EX girlfriend under any circumstance or you can prove what a crappy friend you really and truly are. There are a few other "Commandments'
1) Don't lie to your friends
2)Don't dodge your turn to buy a round of drinks
3) Give a guy a four foot putt
4) Don't steal his jokes or his move
5) Don't talk about anything other than sports when you're watching sports