Hi. I’m just gonna jump right in

My sister (17) has been doing a lot of work to prepare for college applications. Buttt she procrastinates a lot and isn’t very organized. Today I was in our study room (two desks and a couch) reading a book. My sister came in and said she had to work on an essay. I said okay. She asked if she could use the couch. I said since I’m not making any noise, maybe she could use her desk. She replied saying her desk is too messy. (It is incredibly messy. Books all over, wrappers, a gross blanket, tons of random supplies, and so on. Her desk is bigger than mine but it’s literally unusable because of everything that’s on it). I said (a bit snarkily to be honest) then clean it. She mimicked me and walked out.

I finished my chapter and was really

Hungry so I started making lunch for everyone. Put out plates, napkins, forks, drinks, fruit, vegetables, and so on. My Mom came in and started yelling at me saying what I did was completely awful. That my sister has mascara streaks down her face and is completely stressed out. She said her essays are more important than my dumb book and I should’ve moved. I replied by saying I was there first, I wasn’t being loud so we could’ve co existed, and she could’ve used her desk if she cleaned it (or at least temporarily moved her belongings off of it). My Mom said my sister is very behind and adding to her stress doesn’t help. Then my Dad chimed in saying he was planning on helping her clean off the desk this weekend. I don’t even remember everything else it just happened so fast. All I know is my Mom went out to eat really angry at me and now I’m eating awkwardly with my Sister. Or well, I’m supposed to. Im currently sitting on the bathroom floor typing this out.

I feel like I didn’t do anything wrong. My sister always does her work in her bed or on her bedroom floor. Plus it’s OUR study room. She could’ve used her desk if she wanted. I was going to leave when the chapter was over regardless of lunch. And reading a book isn’t a loud thing. My sister also spent three hours after dinner yesterday watching TV after working for only two hours on her essays (hence why she is behind)

Can someone please help me? Either tell me I’m not loosing my mind or explain why I’m in the wrong