When Karens put negative energy out into the universe, they are bound to get that same energy in return. Here, we have a Karen who purposely disregarded her son-in-law's dietary issues and served a Christmas dinner with nothing for him to eat. He never forgot that feeling and it wasn't until a decade later when he finally got some payback. Sure, it's polite for a guest to eat what is served to them, but in this instance, these were known health issues that the Redditor made sure his monster-in-…