What I’m expecting next chapter: Asumi lies to Nanao about having work that night so she can go to her reservation, Nanao gets suspicious and follows her, sees her heading into a hotel with another girl (if the girl’s butch enough she might assume it’s a man), but because Asumi said she had work Nao will assume that she’s the prostitute.
If she’s feeling really protective, she might even try to intervene then and there, though that would resolve the misunderstanding immediately so i doubt it.