MY roommate is a BITCH

I was on Instagram going through random accounts of people that go to school with me (I’m in college) and I came across an account that is friends with my roommate. One picture that stood out to me because it looked familiar so I clicked on it. Turns out it looks familiar because they were all on MY BED with half of my sheets ripped off. I usually go home on the weekends because I live in state, and I like to do laundry at home. How I know it’s my bed is because I have a black bag hanging at the headboard and I have stringed lights at the end. How the hell do I bring this up to her??? Like I can’t just be like oh yeah I saw your friends on my bed on Instagram. Should I just be really fucking blunt? Like who even does that shit? We aren’t even close and it’s common sense to not do shit like that because it’s rude.

EDIT: I’m also really upset because this isn’t the first rude thing that she has done. In general she is very inconsiderate. She will talk loudly on FaceTime while I am sleeping, she will bring her friends over while I am sleeping, we agreed to let each other know when we are bringing people over but she never lets me know, she likes to make out with a guy in our room while I’m there, she left a guy alone in our room, etc. This was just the tip of the iceberg.