Ahhh bad roommates...just recently, I lived with a girl that I didn't really know very well but I wanted to move off campus and she needed a roomie. It was a great and wonderful for a while, she never went into my room or ate my food, etc...without my permission. Well, I wanted to get a dog and discussed it with her for about a month before actually looking into getting one. I even let her help me decide which dog to get, she went to the shelter with me and everything. Well, after getting the dog home, I started crate training and she would
leave my dog in her crate when she was home and I was not

When she got back from a beach trip, she left a box of granola squared with chocolate on them in the floor, well we stepped out for a few minutes and left my dog on the couch. When I went back in, she had eaten 2 or 3 of the squares. What did the roommate do? Did she apologize? Nope, she started yelling at my dog for eating food she left on the floor!
Also, this girl couldn't cook AT ALL, she cooked hot dogs on the oven rack with no pan or foil and wondered why the oven always smoked and made the smoke alarms go off...

When she finished cooking with a pan, she would immediately take it to the sink and run it under water (it warps the pan) and put teflon pans in the dishwasher (seriously, who does that?!).
Then, two months before our lease was supposed to end, she decided that she wanted to move into an apartment with someone else to "help her out" because the old roomie had moved out after graduation. She offered to still pay her part of our rent but considering her parents paid her bills and she quit her job shortly after making this decision, I decided to just find my own place. Needless to say, I'm happily living in a 1 bedroom apartment with my dog and happy as a clam!
