You mean the scene at the secret onsen, right? That scene requires Mira and Mirel's events at the Thremten festival and their relationship high enough, and due to the different requirements is not something you'll usually find immediately after getting the characters. The reason why they act that way in the onsen is also explained by the old man, as it is not a normal onsen.
The scene is required for other scenes at the onsen, of which currently only one exists, because the other choice is to close the peeping hole and thus removes the option to see any scenes that happen in the bath for Ryen.
I don't understand how having to skip through the dialog of one scene you don't like ruins a game of this size for you. Maybe take a little break and continue now that you're past this point.