What actually Happened
Sebastian decided to stay in a hotel outside the pack house, not having had a great experience here last time. He felt as if it was easy to get succumbed into the madness of the pack business without even doing much. Feeling stressed by just the thought of it he decided to go out for some drinks. His tolerance was pretty high, even for an Alpha, and thus he enjoyed drinking from time to time.
As a troubled teen, he picked up bad habits pretty easily. Drugs and smoking were one of them, and given his wolf status, he was pretty tolerant. Thanks to his high metabolism, never did he ever get caught in a blood test. By the time they took the blood, it was already clean. All of that changed when he ended up auditioning for a small commercial which was held on his college campus. Thanks to his looks he gained quite the popularity within the locals and decided to embark on this new career path.