Apparently once you reach high enough corruption, you can ask her to striptease. Once you have bending level 2 and have unlocked panty modeling. She has to be excited as well. After this part, I don't really know, I'll see if I can figure out what's after this. God this game is bad.
EDIT: After this you unlock bending three after some amount of corruption goal the game doesn't tell you. Which I believe completes stage 1?
Great game design I love that the game doesn't tell you when its safe to click that button without getting an insane negative debuff to her mood. Fantastic how clear that was.
It tells you when literally anything else is safe roughly speaking but not that scene which is just terrible design really.