I believe it was Chapter 9 in the book where Colin and Penelope actually had their first kiss in the Drawing room inside the Featherington’s house. Not exactly the same as the show, but their dialogues during that scene followed the book 💗✨
Also in another chapter (I forgot.. I think 15?) Spoilers (from the books) . . . . . . . Colin almost ate up Pen in the Bridgerton’s drawing room 😂 Before the wedding even happened