Bachelor parties are an essential part of male bonding. It’s a last chance for all of your buddies to tell you that you are making the single hugest mistake in the history of time. So it’s important that everybody be comfortable and have a good time. That goes double for the groom because it’s probably his last night of free-wheeling fun until the ink dries on the divorce papers (it’s not cynical–simply look at the numbers). Fortunately, it’s easy to have a good time so long as you keep from making any of the following mistakes.