This takes place in s4 of Teen Wolf

You were Scott’s younger sister, and had just started as a freshman at Beacon Hills High. You knew about the super natural elements your brother deals with, with him being a werewolf, but you were human.

You were at home catching up of some homework, when you heard voices from the bathroom, curious you went to go look.

There he was Liam Dunbar. The boy in half your classes tied up with duck tape in your bathtub. To say you were embarrassed was an understatement. Scott was there along with his best friend Stiles

“What is going on?” You asked your brother which brought you outside the room.

“Listen it was a life or death situation so I bit him, so now he’s my beta, he just doesn’t know it.”

“Can’t you explain this to him without tying him up??”

“We tried, but it’s the full moon and he won’t be able to control himself. He told you and you stormed back into the bathroom where Stiles was trying to calm down a very angry Liam