Way back a few months ago I suggested to my friend that we should room together next year. I started looking at housing before the College school year ended, but I never found anything. Now it's been about 3 months since I suggested, and he approved, of trying to room together. He hasn't put any effort into looking towards housing. I on the other hand found something for myself, and I need to tell him that he needs to find housing for himself next year. This however, I see is a breach of trust, even though he didn't put any effort into looking for a house, I still feel somewhat obligated to help him find something. This goes doubly so when you consider that the College semester starting up in about one and a half months now.
How do I tell my roommate that we aren't rooming together next year, even though I suggested the idea? Preferably in the politest way possible.