I had guests who flooded the bathroom by leaving the shower curtain outside the bath, and dropped their sodden towels and used dental floss on the floor, all presumably for me to pick up. They also let their dogs on my furniture. All this while they were renting their own house out to take advantage of a local music festival. They made $5000 over three days and gave me a bottle of wine. No longer on my Christmas card list, needless to say...