you and Eren are watching some videos, and you quickly get up to go to the bathroom. Eren looks around your room and sees a book on your side

He picks it up and flicks through the pages and sees some surprising sentences in there. He laughed and blushed, waiting for you to come out

You came out of the bathroom and saw the book in Eren's hand, he smirked

"Oh so this is the stuff you read~?"