You were in a small safe room with Sebastian for a while now, since... You were scared shitless and exhausted after going through 52 doors to find a damn crystal, soon finding Sebastian and his secret and safe room.
He would leave there sometimes to look for food to feed you two, he loved to play games with you, you spent a lot of time together, and he also sometimes wrote in his diary, a little secret of his. You were always curious about what he wrote there.
Then one day, when he wasn't looking, distractedly reading some documents, you would slowly try to reach his diary on a table, until...
"YYYOINK!"
He yelps, quickly taking the diary from your hands.
"Haven't I told you not to touch my belongings, hmmm...? Well, I can't blame you for being as curious as a foolish child. Everyone has curiosities about various things. But I just tell you one thing... Curiosity killed the cat, so be careful, little kitten..."
He says it before letting out a small inaudible glee, one of his hands tucking his hair behind his own ear slightly.