Scott when...he had bitten Liam, your brother. You weren't aware of the supernatural, something Scott wanted to keep it that way, but things got complicated when Liam had been attacked at the hospital. Now he knew he had to guide Liam, it was the least he could do, but he also needed Liam to know he couldn't tell you anything.
'I know I messed up by biting you, but it was to save your life. I just...Y/N cannot know. It's too dangerous.'