The Straw that broke the camel's back

Can I just say I almost lost my shit at my current roommate today. I have let her move in with her two YOUNG boys. I have babysat, lent my car out, shared groceries, shared my time, cleaned up poopie diapers... I mean really what haven't I done you ask? The answer is nothing I can think of. Well tonight we were talking about moving out and I mentioned that the oven needs cleaning, and she says "well I didn't make it messy". I have to be honest I wanted to fucking scream. She uses the oven every day just like me. We cook the same meals together all the time but somehow the mess is my fault. I couldn't believe it. I was pretty sure I wanted to scream at her. I can not believe this is who she is. She has thrown my life upside down and now tells me the oven is not her mess. I know that this may seem like a little thing, and perhaps it is. But it may just have been the straw the broke the camel's back. Yes in this analogy I am the fucking camel. I mean on Wednesday I am babysitting for her. Ask me what I did on Saturday.... oh that's right, I BABYSAT her kids! OK, obviously I am a little wound up here but I thought it is important to share things like this. Get them off my chest before I explode.