A bit of extra context. When he asked Douki-chan if she’d like to go somewhere to warm up, he used the term 休憩. This is also the euphemism love hotels use for a short-term stay.

Douki-chan's thinking she's going to put that red underwear to good use.

Ah, and now her eyes can turn purple-pink, apparently. I guess that's the color of ero thoughts...