Is it wrong that I think the other kids crying over the game is a bit funny
Why do you find it funny?
Well, I burped at the same time as he did and I found it funny that they say he lost.
It's inappropriate to laugh at someone who feels bad or hurt. This will cause the person to feel more hurt and embarrassed.
I probably shouldn't have laughed but I couldn't help it at the moment.
Laughing out loud about it will only make the other kids resent you. Instead try being a good sport, and offering to play again.