Moral Dillemma

[TheCroShow]

k so i'm chillin at my computer yesterday when i get an msn message from my buddy

[ QUOTE ]
Buddy:
yo dude wanna play poker tonight? me and some co-workers are gonna play, should be juicy...they're all total fish

TheCroShow:
yeah man i was just sittin around watching the paint dry, when is the game?

Buddy:
i'll pick you up after work and we go straight there.

[/ QUOTE ]

So i was doing nothing and agreed to go and play poker with his buddies. 3 hours later I'm $100 richer in a SNG style tourney. (BIG WINNAR!)

now am i obliged to give my buddy a cut? maybe give him back his buy-in? what's the etiquette here? all has been said and done, i wanna know other opinions. in case you're wondering, they invited me to their next game.