Having people over is risky business, sometimes the most fun people end up having far fewer manners in the privacy of your home. Nothing kills the vibe of a friendship quicker than realizing they have absolutely no respect for other people's safe spaces.
Sadly, for every dreamy houseguest, there's a chaotic person ambling about the world, ready to break things and invite rude strangers into your living room at the drop of a hat before emptying your fridge. Luckily, the internet provides a cathartic space to air grievances about all of these nightmare guests.
I had my girlfriend, and another now ex-friend came over to my house. My grandmother on my mom's side lived with us at the time. She had advanced Alzheimer's, and could only communicate with basic phrases. She was so bad, she would pat people on their backs and say "good, good, good." She also walked around with a zip lock bag of Q-tips that she would hand out as gifts.