They know that you will eventually have to pay the pills, clean the house, and fix things because you are the only one of the pair that cares about living in a sty.   Yep. I lived with a slobbering sow for a year in college. Every month it was, "Where is your half of utilities?" He just knew that it's not like I was going to let the electricity shut off.  But the worst is the food bill. And anyone who has ever had the misfortune of living with a slobbering sow knows all too well that horror. Couple of college kids so why not just split groceries? Yeah, good luck with that. Get groceries on a Saturday and you'll be out of food by Monday even though all you've had was a bowl of cereal in the between. Rest assured the sow will continue to feed though. It will bring home bag after bag of take out, not even having the common sense to at least just go buy groceries, bag after bag of take out, despite owing you for three months utilities.  So inevitably you will try the "each have your own shelf" idea. Good luck with that. Your shelf will probably have some normal stuff on it. Things like milk, eggs, etc. The sow's shelf will be full convenience food that it will feed on constantly. Oh and cheese. Endless cheese. Sows all love cheese for some reason. Anyways you will come home routinely to your shelf having been raided so the sow can have made brownies (or whatever the blob of the day is). There will be a note that reads: "Borrowed your milk and eggs to make brownies, but you can have some." You will have had a full carton of milk and a dozen eggs. Both containers will be empty and in the trash with only a third of a tray of instant brownies that you didn't want and whose package called for one egg and a half cup of milk left to show after the sow fed. There will be milk splatted on the floor, along with chocolate syrup, because it wouldn't have drank just plain milk. The lingering smell of fried eggs is in the air. Luckily you're so disgusted you have lost all desire to eat anyways.  Finally you will just stop buying food. It's just easier to go out and specifically get exactly what you want to eat at the time of eating than deal with keeping anything edible in the house. This may be the only time the sow will show any sympathy towards you, because it can't understand the concept of not having ready to gorge things on hand at all times. It won't do anything actually helpful, but it will make its best sow-ian effort to be kind towards you. This will include offering you some of its food. Of course its food will include things like canned cheese and pizza bites that you have to cook in an oven to consume safely but, "They're fine in the microwave," because the oven might include some vague semblance of effort.  Eventually your friends will begin to wonder why you look you're slowly starving. You will half to explain to them that you are.  On the other hand if you ever decide you need to drop a quick clothes size for that beach trip or class reunion or whatever, rooming up with a sow for even a short time is guaranteed to do it.