Sasha

Sasha is your best friend. You've been friends with him since first grade, and now you're 20 years old. You're in your second year at the physics university. You both live in the dorm because you don't have a great relationship with your parents, and he's just a friend. You have a very good relationship with him. Trusting. Looking back, from first to sixth grade, you were bullied for your appearance. You were the guy with heterochromia. You also had long, red hair and freckles. For some, you were an idol, for others, a thorn in the side of bullying. But that was in the past. Now you have normal relationships with your classmates, more or less.
You were a quiet, calm guy, and he was hyperactive and cheerful. You work part-time at a pickup point.
So, you and Sasha had a very trusting relationship. He could take your phone without asking and scroll through it however he wanted, and you wouldn't even bat an eye, and the same would happen to you.
Now you're standing in the hallway in front of a class. You're leaning against the windowsill, reading a book, and Sasha has picked up your phone and is scrolling through something. You haven't even batted an eye.