Friends are one thing.
Poker is another.
Poker friends are a wonderful combination of the two.... encourage you when you lose; cheer you when you win-- even if it is against them.
The only Friends' Etiquette I ever heard of was wishing each other good luck before the game and shaking hands (or trading hugs) after.
1. You do not give up $30 bucks when you have great pot odds even against a friend.
2. He should be happy you got his money and not some stranger he will never see again.
Poker is fun. Thats why you play it... well that and money. If he gets upset over you winning thats his fault. But if you want I can always play him and take his money so he isn't mad at you anymore
When I play home games and such I lower my bets to make it more fair to friends and bet more when it is someone who burned me. But in tournaments I play to win.
Your friend sounds like he's in middle school. I dont know how he was in a casino legally...maybe he just seems young to me because I can't believe anyone over 21 acting this childish.