With a good attitude, a high sensitivity, and it not being too late at night, she'll sometime ask you to have sex (and be in a bad mood tomorrow if you say no). Same conditions can lead to a scene in the shower if you're washing her back and start jacking off, she will either start a blow job or have sex. It should go without saying that both of these also require sufficient trust and sexual interest to even unlock these acts, but just gonna add that as a clarification. Oh, there's also walking in on her in the bathroom which leads to eating her out and you getting a blowjob, initiated by her.Someone knows if there is a way to "corrupt" the sister? Like making her asking for it?
Beyond these however, it's about as corrupt as she gets. She's kind of dirty once you begin a sexual relationship, but she's never really corrupted. She's still relatively innocent and nice.