Bee stings don't take ten minutes to hurt...
...and thus, gags like this shouldn't take more than 30 seconds to make someone laugh, GUYS.
I agree with you, man. This thing's already long enough to suit the purpose. It's not a drawn-out story, it's just a quick sting gag. And you pulled it off very well; I chuckled when karma came back and bit the guy in the butt.
I was a bit thrown when the credits rolled, but considering it puts the main attraction right in front, I don't mind it.