loosen the connections to the modem/wireless router, some appliances they'll be sure to use, etc. Enough to where it looks plugged in when they check, but it isn't
Variant on this one, adjust the float valve on the toilets so that they just barely cause water to constantly go down the overflow drain.
Take the aerators out of the faucets. Switch the hot and cold supply lines under the sinks. Turn the light switches upside down. Loosen all the cabinet knobs a few turns. Adjust the toilet float to put as little water in the bowl as possible. If the dining room chairs have those little plastic bumpers on the feet, take two off each chair.
Back off a few set screws a bit so that faucet handles come loose/off when used. Loosen off the nuts that hold the toilet seat in place. Take a few doors off their hinges and adjust the hinges so that the doors are slightly out of alignment, so they won't close easily. Along the same lines, fuck with some of the internals of door knobs/handles to adjust the throws to be too short, too long, gritty with gunk, etc. If there are any ceiling lights with a cover over them that would collect bugs/dust, apply dead insects to make it look bad. If no dead insects are available, take some sort of fruit juice or something and wipe the inside of the light cover to attract said insects after you leave. If there's a fireplace, place a dead fish up the chimney. Blame birds/squirrels, etc.
Holy shit... right for the jugular... What's wrong? Have a camera shoved up your ass recently or something?
Nah, hot as hell out here this week so all the guys are bitchy which makes me irritable. Add in a few hazys and you get one mean, sadistic bastard.
I was going to say "Fuck his daughter" but not sure how old she is and not trying to be put on a list.
Flipping switches and supply lines and stuff is too obvious and permanent, and nothing that could occur accidentally, so I'm guessing he'd figure out it was me. I had already considered messing with the router/modem but it's not installed in the apartment. Toilet, faucet door and chair alterations have been noted. We have already considered leaving a trail of juice/sugar water behind to encourage bugs. All good suggestions. She's not hot enough to be used as revenge. Although maybe if I get to put it in her exhaust vent...
As I'm running an AirBnB, here's some things that REALLY annoy the shit out of me when I'm cleaning between guests. Hair. Everywhere. An unreasonable amount of soap scum on all of the faucets. You stayed here for 2 days, did you finger paint the shower walls with soap? Women who use the hand towel as a makeup remover, even though we provide make up remover wipes. Wet clothes left on wood surfaces. Greasy finger prints on glass surfaces. Some things you can do to piss them off - Take all of the batteries out of the remotes. Hit the test button on any GFI outlets. Turn the anti-scald device in the shower all the way down so the next person only gets lukewarm water. Pour hot coffee grounds into the trashcan. If you can turn the heat on somewhere in the house, crank it. Leave a few dirty dishes a plate or two down in the stack or leave really big lipstick marks on all the glasses.
Ohhh... devious. Intentional long hair plug in the shower. Oh... or, boobs smushed up against the glass surfaces in the bathroom, so when it gets humid, you see boobies and nipples everywhere. Shower stall doors/windows. Mirrors. Full length mirror in the bedroom or hallway? Nipple grease smears. You can only hope they rent to a hardcore (but not hardcore) Christian family before it's cleaned.