I'm stuck at level 2, 2000 corruption. I have a very vague idea that I'm supposed to convince Kelly to go without panties to get level 3 corruption, but I have no idea how.

Nevermind, not sure what I did. All I know is to make sure you do the event where the succubus realizes that Viki reached corruption level 2. I think that is what did it.

how did you get that event? I've had nothing new for days. 

I got Viki to level 2, then one morning, the succubus was all like "Oh, she's level 2 now, let's do something with her."

do you know how high you had to get her corruption in order for her to get to level 2