To get the book room scene, you need to have the book room placed in the inn, and then there's about a 1 in 5 chance for Cami to visit the inn at night (time slot 4). You'll see her on the map screen being at the inn, then go into the inn building screen, click on the book room, then click on her mini figure to open the scene.
I'm going to add in the ability to spend the night with all the girls sooner or later. Look forward to being able to invite Vera to spend the night in the coming update! More kissing and petting will also be coming soon!
Glad to hear you're enjoying the game!