Full Crazy Mode
My worst guest was an ex-friend of mine. This was after trying to help her for months. At one point, my girlfriend and I let her crash at our place for two weeks while she sorted her life out before she went into full crazy mode. We went away for the first five days of that and got engaged. We came back to our entire apartment reorganized and found out she went through everything. She had taken over the living room and the office by bringing all of her stuff from home to our place.
We thought that she would crash on our pull-out couch and we could help her get back on her feet. Instead, she dominated our lives and seemed disinterested as to ever leaving, and we couldn’t enjoy our recent engagement. She then started to spout conspiracy theories. We convinced her to leave after a few weeks and threw away the rest of her stuff after a few months when she wouldn’t pick it up. Then we moved away soon after and threatened everyone to not tell her where.
Story credit: Reddit/ill_take_the_case