Vegans are fun to joke about, and all, after all, there's something about a group of people that takes themselves so seriously without an ounce of levity or ability to joke about the subject that lends that same group of people to be a prime target for humor. Heck, there's a reason why community discussions about vegans and jokes about vegans are everywhere on the internet. That being said, if you know that your friends have something that they're humorless about, it's hard to be surprised when…