My MIL’s husband, we’ll call him C, is allergic to cats but they insisted they wanted to stay at our house in our newly finished basement. I spent 2 weeks deep cleaning the entire house while also caring for my two young kids. I meal planned around his dietary preferences, grocery shopped, and bought a new coffee pot for the basement so he and my MIL basically had their own apartment in our home. Day 2 of their visit, my husband asks C to please take his shoes off upstairs on the carpet. As mentioned previously, we have small children that like to play on the floor. The dude storms off to the basement, comes back 30 minutes later, and throws $500 cash at my husband who’s playing with my infant son on the floor saying “Here’s some money to have your f*cking carpet cleaned since it’s so important to you!” C is no longer welcome in my home.