There was a lewd scene at the end where they are dog sitting in the dean's office. People thought it was out of character for her at this point (kind of ignoring the party scene but you know). It's still there in the scene gallery, I think, so you could unlock it, if you haven't seen it.
Well, I tested this and yeah, if the scene isn't in the gallery, it can still be unlocked.
As a personal opinion, I think people believe that Penelope's scene is out of her character, not necessarily because of the scene itself, but rather its 'placement', aka the dean's office. While I admit that I'm a Penelope simp, during the date with her, it's revealed that the dean might have a grudge against her, after the hacking trial. However, the dean asks Penelope to take her of Oscar, her new dog, in an attempt 'to make peace'.
My point is that the possibility for Penelope to throw away a given chance to be in the dean's good graces, when she's asking for her help, is the actual part that is considered out her character. For those who remember, Penelope is considered a very caring girl, who wants and likes to help other people, at any cost. She is also shy, and for this kind of personality, the best process is to take the things step by step.
While I agree that shy persons can make some crazy stuff too, I think that the dean scene is considered out of her character, also because in this instance, Penelope's personality was taken to the opposite side of the bar like instantly, by completely omitting the 'one step at a time' process that I've already mentioned.
As for the party scene, well, I guess people don't talk too much about it, because:
1) It's a students party (it's Lauren's birthday and Halloween party actually), and sex is very common in this case
2) The party is in a sorority house, the Deers' one for this matter, but a sorority is still a sorority, and sex happens a lot there aswell
3) This is kinda far fetched, but the MC is asking for her help and she accepts that, although this help is a bit conditioned
Again, these are just my personal opinions, I don't know how much true they are