Nuka: "Um, Miss Dotty, I brought you a flower." Dotty: "Aren't I a lil' old for ya, kid?" Nuka: "Oh no! I may be small now, but I will grow big and strong and I will protect you from everything!" Dotty: -giggle- Nuka: "You....Your laughing at me?" Dotty: "No, Nuka... No... It's very sweet, thank you for the flower."
I imagine that Dotty was older than Nuka and if there was a thing between them it was because Nuka had a crush on her from an early age
