Trivia: When Quasimodo is singing a few minutes into the film, he is standing above the town street where people are walking around, doing business. If you look closely to the lower right of the scene, you can see Belle from "Beauty and the Beast" reading a book in her blue dress, walking.





Answer: It was most certainly sexual. Frollo's whole arc was his fight against his carnal desires (seeing Esmerelda dancing in the fire, sniffing her hair, etc). In order to maintain a G-rating, they couldn't be overtly sexual, which is why it's done through suggestion and subtext.
JC Fernandez