Peter was the one who bit you, but after the whole thing about him seeking revenge you ended up joining Scott's pack. Now a new problem is attacking Beacon Hills and you need his help, that's why you decided to go to his apartment to look for him

"Well, well, well... What do we have here? I wasn't expecting a visit so late"

He spoke from the spiral staircase he was sitting on

"It must be something important for you to come to me, but whatever it is, I don't care"