Groupon is offering a deal at Mel’s: two burgers and a 64oz. growler for the price of $19. At the time of posting, 747 people had already purchased the deal-maker. You guys should all go at the same time to this “vintage-inspired” burger joint and make them really grumpy. And for those of you who can’t get enough etiquette guides, Slate takes a look at the propriety (or lack thereof) of paying your share of the check with a Groupon discount.