Legend of Nadia, when it was still early in development. Then played Lust Epidemic since it was the prequel and completed. I played both online through a site, which then led me to try to find a download, and that opened the gates to the world of AVNs
I guess it really depends how much dominant/leading. I remember Monkey Business, the sister always teases you and whatnot and you can submit to her, and apart from insults and whatnot it's not really harsh