(erm so I accidentally made light left handed here because for whatever reason I flipped the ref pic of him writing I guess ???? And I don’t want to flip the final image cause it just wouldn’t feel the same so I suppose maybe he’s just trying to show off here and that’s why he’s not holding it with his dominant hand. Explains why he ends up dropping it too)
I like to think of what L would do when he starts being curious about you.
It starts with small gestures, like him handing you your cup of tea or a plate of his sweets. He'll make mental notes of which desserts you like or what kind of tea you prefer, making sure to get you what you're craving next time.
Like, he'll maybe pull on the stray strands of your hair and stare. Oh, the endless stares as he presses his thumb against his lips, like he's trying to remember every detail of you, every freckle and crease on your face, every different wrinkle it makes for each corresponding emotion.
Or whenever you're out of view (late to meetings, not within the building, gone in the room for too long) he'll wonder where you are, asking around "Have you seen Y/N?" Then you come around and you can see his face brighten ever so slightly when you approach him.
And he'll start to prefer perching on the sofa over his singular occupant couch from then on, because he wants to be next to you. He does not know why yet, but being next you is pleasant, that he's sure of.