Bookish, socially awkward characters show up with glasses, messy hair, and a put-together-but-dorky vibe like button-up shirts, ties, or a pocket protector. The sex often plays on a “shy brainiac getting pushed into it” angle, with lots of blushing, fumbling, and then surprisingly desperate fucking once they get going. Sometimes the contrast is the whole point, with a confident partner teasing them, yanking them by the tie, and making the quiet one moan and cum hard.