How the manga handles Erina in this chapter feel very off for me. First, she's essentially coerced into having sex on video while she's having a crush on someone else. Second, she is then made to do it while her crush watches her. This feels rather disturbing to me and no matter how eccentric she is, I don't think anyone would just brush that off and behave like nothing's wrong. Generally the way Erina is treated in this manga feels off and she seems to be just a plot device for the Mamoru+Azusa pair.