If you've ever lived with one or more roommates, you know that things can get a bit messy and tense. Now just imagine the kind of jerk pranks would get pulled if you both had Portal guns.
Oh sure, it'd be tons of fun at first — until you get cake thrown at your head or your jerk roommate punches you in the jaw. The dudes at RackaRacka made this video to prove just how hectic things would get in that situation.
And if you've never lived with roommates at all? I kinda envy you.
Portal Gun Duel via RackaRacka