Mia's POV
When my mother told me she was getting remarried I didn't blink twice. I was eighteen and only had a few more months until I was leaving for college anyway so her new husband and his new daughter weren't going to blow up my life.
Or so I thought.
Sabrina was nineteen. She was already in college. Well now she was home from college for the summer. My mom was making us share a room until we both left for school in the fall, which means we have from May until the end of August to be the close step sisters our parents wished we were.
It was 6:30 am and my alarm just went off for the last day of school. i looked over and saw Sabrina still asleep in her bed and silenced my alarm to try and keep her that way. I hated getting ready for school with her home, I always went to change in the bathroom and had to be super quiet.
This morning I was extra chirpy because it was my last day of senior year. All the girls dressed in their college t-shirts and the shortest shorts we could find to break dress code. It was a tradition I wasn't willing to break.
I looked around my room in the dark trying to find my t-shirt for Penn State and anger ran through me as I realized where it was. Sabrina had it on. I shook her awake annoyed with her and she stirred moving her blanket, exposing her bare ass to me with her back to me now.
I bit my lip debating on waking her fully since I was enjoying this view more than i cared to admit. I shook the thought out of my head as quickly as it came in and then shook her again.
"Mia what the fuck do you want?" She groaned and the sound made my pussy heat. I bit my lip trying to calm my voice from the anger and arousal.
"You're wearing my Penn t-shirt, I need it for school." I seethed and within seconds she was sitting up annoyed and pulled it over her head exposing her huge breasts making my face go red. I wasn't used to seeing her naked. This was the first morning I had actually been around when she was waking up so I had no idea she slept in just a t-shirt.
"Take it, and let me go back to sleep." She mumbled and turned back over pulling her covers back over her. I couldn't get rid of the blush on my cheeks as I pulled the shirt on over my sports bra.
*****
The whole day at school all I could think about was Sabrina. All my friends were meeting up tonight for a huge end of school party so I had the afternoon to myself before I had to leave the house again. I got home to an empty house and sighed in relief. I needed a release. Sabrina's body had been on my mind all day. Our parents worked late during the week and Sabrina had been out catching up with her home friends so I knew I had time to myself.