I've got my mate's house keys.

[Alberon]

MASTURBATE EVERYWHERE.

But everyone already does that anyway. Right?

[Pijlstaart]

He is lying, I am the real keys, and I am tucked up safely in bed.

[tookish]

Open all his photoframes and blu-tack little pictures of your own face over all the faces in his photos. See how long it takes him to notice.

[Cerys]

Remove the lightbulb from his fridge.

Create a miniature garden in his washbasin.

Fill his toilet cistern with washing-up liquid.

[Steven]

Video yourself putting his toothbrush up your bum, then put it back and send the video to him a couple of weeks after he gets back.

And also forward a copy to machotrouts.

[RoadMaintenanceTycoon]

Brick up the windows and break every bulb

[Spoon of Ploff]

Replace everything in the house with an exact replica.

[José]

[New Jack]

Get his mobile phone and swap the names of his mum and his girlfriend and send the girlfriend a flirty text and ask his mum what she's wearing

Cunt probably hasn't left his phone though

[Cuellar]

Get the whole place rewallpapered with pictures of you dipping your nuts into a dead relative's mouth (his) and giving a 'thumbs up' to the camera.

Hide in his cupboard and when he comes home jump out tie him to the bed and just leave him there to die.

Do a 'Se7en' i.e. hide in his cupboard and when he comes home jump out tie him to the bed and watch Se7en with him.

Fiddle with all the tuning knobs on his wirelesses.

Literally smash the entire place up with a sledgehammer.

Kill a tramp and bury him in the back garden then call the police after your mate has been back for a few weeks.

Replace his favourite chair with you and when he goes to sit down he'll sit down on your lap instead!

[machotrouts]

Replace his favourite chair with you and when he goes to sit down he'll sit down on your lap instead!

I also would hate this.

[metaltax]

Buy a birthday card which has an electronic tune/noise in it and glue it shut with a tiny dab of sugar water. Drop it down the gap between some cupboards or behind something that's really difficult to move and let time do the rest.

[New Jack]

Have sex with his house

[Icehaven]

Open all his photoframes and blu-tack little pictures of your own face over all the faces in his photos. See how long it takes him to notice.

When I went home for Christmas I stuck one of those shiny ribbon stars you stick on presents over my face on an unflattering picture of me that my Mum has on her living room wall. She noticed in March. 

[Replies From View]

Put a lung in a sleeping bag

[a duncandisorderly]

the do nothing but pretend you have is my favourite, followed by light-bulbs & saw something on the computer.

[Mr Farenheit]

Build a wall about a metre from the inside of the front door. Finish it nicely with wallpaper. Then fill the rest of the house with concrete.
When he gets back and opens the front door then that's i. That's your house mate, about one metre square, no plumbing, no furniture, can't even lie down. How much do you pay for that mate? Are you mental?

[mothman]

I also would hate this.

Bet you wouldn't.

[machotrouts]

I apologise for my horny posts in this thread... they were inappropriate and I'm going to stop doing them

[machotrouts]

Brick up the windows and break every bulb

HE CAN BREAK MY FUCKING BULB ANY TIME