Skyfarm & Ryusei Takahata: "How can we follow up the chapter with the naked little girl who was SA'd and tortured to death? Oh, I know, we'll start off with even more rape and death, then immediately transition into a scene where one naked teenaged girl gets molested by another naked girl who looks like a preteen.
Brilliant!"
Being flirty is no guarantee of having romance feelings and this is a erotic manga where pretty much every girl appears nude at least 1 or 2 times, she not bothering cover up could have just meant she has no shame.
This chapter was the first time she actually came out and said she's interested without beating around the bush or being vague.
She was still shown as being clearly embarrassed, though. She just didn't move to cover up nearly as fast as her usual quick-wittedness would otherwise suggest.