Well, yes they did it at this point of the story. They were both attracted to each other so just like in the manhwa, FL waited for the ML to have tea. Then, they started kissing and they went to ML'S room. The FL said she didn't have much experience in this sort of thing (she didn't want to admit it was her first) and the ML said don't worry I'll do it well. The FL asked if he is not saying it because he has a lot of experience and the ML said it was a rude thing to ask and what matters is that its their first time together. While doing it, he saw blood stains and found out it was her first time and that Jiho was not her child.

In the novel, they slept with each other