The bathroom-lingering gets creepy pretty fast. Stiles is sharply funny, with endless thoughts and arguments that keep Derek reeling and intrigued. His rather appealingly built body , his traitorous brain whispers, but Derek does his best to ignore it. He manages to stay in his desk through the end of the lecture, but instead of hanging around to engage in further discussion with his professor, he gathers up his books and bolts back up the hill to his dorm. And, as the weeks wear on, the conversations often stretch out so long that they end up in the bathroom together, Derek brushing his teeth while Stiles showers, or, more and more often, with the two of them showering in neighboring stalls, talking over the water. He irritates Derek so much that he starts responding, asking questions, trying to find reasons to dislike him.
See, that’s what the app is perfect for.
If he ever thinks about Derek, outside of those few minutes in the shower, when he pauses to write back.
He stops to toss his things on his bed, then flees to the bathroom. Derek considers it a few times - even writes his name and room number on the tiles once, turns his back to it and scrubs roughly at his hair, then thinks better of it and wipes the invitation away. That conversation takes some time. He waits for the wave of panic to strike, expecting to feel overwhelming guilt and anxiety over losing contact with the most interesting person in his life.