<human>: I was at my boyfriend's all weekend. Last night my roommate texts all of us to ask if she can have friends over to pregame. I say I'm cool with it because I'm not home. Other roommate said it was fine. Fourth roommate said she wasn't home either. Alright, whatever. 

Came home this morning. My air mattress was blown up in the living room. Roommate's best friend was laying on it and he was talking to one of their friends on the couch. Apparently this guy had alcohol poisoning the night before and couldn't make it back to his dorm (we're on a college campus).

I brought that air mattress for myself. I usually keep it at my sister's apartment so I can use it whenever I sleep over but I brought it here a week ago so a friend could use it. I also have a pillow and a comforter I bought explicitly for that reason. Not only did she use my mattress without asking but she used my pillow and comforter as well. And they were all in my room as well, so she went into my room to get this stuff. 

Am I right to be irritated by this? I mean luckily I do like the guy who was using it, but that's not the point. I probably would have allowed her to use it if she asked. But she didn't. And then on top of that she uses my blanket and pillow. Not for nothing but that's personal to me. I drool on that stuff. I wake up with my face all smothered in that pillow. I don't want someone I'm not friends with using it. 

I asked my mother roommate about it, thinking maybe she did ask but I was too drunk last night to remember. She said she didn't because she had asked *her* instead of me. So she took my stuff then asked our other roommate permission to do so. But this kid was sick so he needed it. I guess they couldn't put him on the couch? 

How do I approach this without coming off as rude?

Give me a shortened version of the text
<bot>: Roommate borrowed my air mattress for her drunk friend without asking. Drunk friend also used my personal blanket and comforter and now both things feel grimy to me. What do I say to her?