I've got my mate's house keys.

[shiftwork2]

Dismantle a hatchback and reassemble it in his bedroom.

[Ferris]

Do absolutely nothing, but heavily imply you did. He'll go bonkers trying to figure it out.

[Consignia]

Do absolutely nothing, but heavily imply you did. He'll go bonkers trying to figure it out.

Do that. Then SMEAR SHIT ON HIS FACE.

[Kryton]

Put an ice cube in his coat.

[idunnosomename]

Basically just shit everywhere like an animal, hurl it all over the place, smear it over your body and roll around on his soft furnishings, screaming at the top of your voice

Top bants.

[Golden E. Pump]

CaB meet?

[Sebastian Cobb]

Someone I know had a slightly mental/stalkerish cleaner who after he sacked her and changed the locks eventually ended up being employed by the new cleaning firm they'd employed.

Anyhow when they was away the cleaner borrowed the keys and let themselves in and put a load of lipstick kisses on the wall. My friend phoned the police (and changed the locks again) and their advice was to chuck all the food out of the fridge and freezer. Makes you think.

[pancreas]

replace all bulbs by bulbs with lower wattage

[Dex Sawash]

Let a ghost in, or do a murder that leaves a ghost

[JamesTC]

Swap every disc in your housemate's DVD/CD collection so nothing is in the right case.

Buy 20 copies of Bone Alone on DVD and hide them in various places throughout the house.

[Fry]

Swap every disc in your housemate's DVD/CD collection so nothing is in the right case.

Buy 20 copies of Bone Alone on DVD and hide them in various places throughout the house.

Mate it's 2018. There's no DVDs in his house.

[MojoJojo]

Drain his heating system and do a power wash, but don't put any rust inhibitor in when you refill it.

[Cerys]

Fill his bath with red paint (water-based), and drain it leaving just the residue.  Then leave a red-stained saw (£1 in Poundland) sitting casually on the washbasin.

[biggytitbo]

Put a poo behind his oven.

[New Jack]

Wrap as many of his possessions as possible in newspaper. Seen a news article once about that legendary idea!

[Dr Rock]

Throw them down a drain.

[Noonling]

Piss in his letterbox.

If he has any photos on the wall, replace them with a photoshopped version so they are with different people or in a different place, e.g. him in a hot air balloon or being arrested.

Can you replicate his handwriting? If so, buy a notebook and write his own dream diary from ten years ago. Make his dreams steadily more insane and disturbing. Be creative. Then place the book slightly under some furniture, as if he could have stuffed it there a while ago and forgotten about it.

Kidnap his parents and/or siblings and make some treasure hunt around the house using their fingers and toes to give clues as to where you've stashed them (fingers are great for pointing)

Soak his bedsheets in hydrochloric acid.

If he has any meat in his freezer, replace it with human meat cut in the same way. Replace any images on the packaging with holiday snaps from your victims and see if he notices.

Go onto his console/PC and delete all his save files.

[king_tubby]

Put his house on Air BnB and then rent it out to a stag party from Skelmersdale. Make sure the telly only shows BBC4, and that there is no bog roll. And only one single bed.

[Alberon]

Take every internal door off and screw them to the ceilings.

Start a cannabis farm in the loft. Tip the police off when he gets back.

Glue all his plates together into one solid block.

If you have the time solder all his cutlery into one big metal sculpture.

[willpurry]

rearrange the furniture a bit... just enough to slightly disorient him/her.

I like this Oliver Reed story.

[New Jack]

Three simple words

Gaslight
The
Cunt

[mothman]

Locate his porn, and, with the help of either glue or Photoshop (depending on whether it's printed material or digital) replace the heads of all the women with pictures of his mum's head, and the heads of the men with pictures of your's.

[colacentral]

Leave a note on the computer saying sorry, you saw something you shouldn't have, but you won't tell anyone.

[colacentral]

Make everything wet.

Create a gas leak.

[hedgehog90]

Create a fake £10 voucher in Photoshop for his shop of preference, print onto paper (find some thin paper that feels authentically voucher-like), cut it out and put it somewhere where he'll definitely find it.

Place a handwritten message in the battery compartment of his TV remote (something mean like 'You smell' or 'Twat person'). Wrap the message neatly round one of the batteries and then apply a layer of cling film for extra adherence.

[mothman]

Back in my late teens, in one of the drawers in my bedside cabinet there was a copy of Vogue or Elle. I can't remember why (possibly emergency wanking material, or maybe I just wanted to cannibalise it for pin-ups). This magazine had one of those peel-open perfume inserts, and over the course of a month or two the smell infused the drawer, and also any clothing that was put in there ever after.

So, you could remove all the clothes from one of his drawers (perhaps the underwear one?), liberally sprinkle a few drops of a perfume on the bottom, leave to dry then replace the clothing. Then when he goes out wearing that clothing, he'll smell lovely.

[machotrouts]

Alright thanks everyone for your input. I changed his desktop picture to a picture of my willy

Haha good one... your willy... that would be terrible for him, seeing your willy, all over his desktop like that. That must be so annoying. I would hate that.

Apropos of nothing, can you look after my house for a week

[Sebastian Cobb]

Biro on bikinis on all the naked ladies in his jazz mags.

[Cerys]

MASTURBATE EVERYWHERE.

[Goldentony]

I know we joke a lot on here but to be sincere Fry mate, you should eat a pair of his undies