See, I don't think that it was being called a whore that would hurt Madeline. I think it was the implication that Adrian was making when she called her a 'wordy version of slut.' Risking gender fail!, in a way, I think Adrian sees Madeline's extra curricular activities as a weakness, as a way to avoid "that when you wake up tomorrow morning you will still be ... what you are." And I think that Adrian knows that Madeline abhors weakness so by throwing out a 'wordy version of slut' Adrian is hinting at a weakness that she believes Madeline has.

I don't know if that paragraph makes any sense or not.

Re sexual fidelity within TR: Paul does seem to be a bit possessive of Madeline during the S2 episode, 'Not Was.'