You're platonically living with a girl.  It's a strictly professional relationship.  Impossible? Not at all!  Here are a few key phrases to guide you through stressful situations with even the girliest of girl roommates:

You Ate Some of Her Weird Food

Tofu, quiches, things that contain no calories— only some of the strange inhabitants of your fridge that look awful when sober, but vanish down your throat under any other circumstance.  Last night you ate a ziplock bag full of something brown that was going to last her a week.  Things to say:  "Who would do something like that?", "OMG you do make the best quiche ever, though" and "How was your day?"

You Left the Seat Up

Men pee standing up.  It's science.  Sometimes pulling your ol' trouser snake out is such a hassle that there simply isn't energy left to put the seat DOWN when you're finished.  But every time your female roommate enters the bathroom you hear a scream because she doesn't know that there's another seat below the first seat. Things to say:  "Pretty sure this bathroom is haunted by a ghost", "Oh, that's what that mysterious toilet ring is for!" and "How was your day?"

She Accuses You of Being a Scumbag for Your One Night Stands 

Women have multiple feelings.  They were born with them.  Some of the positive feelings (albeit few of them) go towards their fellow female companions and suddenly you're a monster for giving in to your night time sexual desires.  You like to show women a good time, then kick them to the curb because of your post-teenage commitment issues.  Your female roommate is a little disappointed you aren't starting a family.  Things to say:  "She practically took advantage of me", "I'm writing a blog entry about it.  I'm fighting a lot of demons right now (begin to cry)," and, "How was your day?"

You Farted in Her Presence

The only reason farting isn't in the Olympics is because every man on earth would be a competitor, and women wouldn't even be able to lace up their farting shoes.  The double standard is twisted, yes, but it works in man's favor: he doesn't have to hear girl farts.  Of course it's rude to display your flatulent superiority in the presence of a lady, so please, keep it in your pants.  Once she falls asleep you may unleash your gas dragons.  Things to say: "Who put a whoopie cushion here and where did it go?", "farting?  How do you even spell that?  With a PH?" and, of course, "How was your day?"