The difference is that Ilya actually cares about the Duke, even if they aren’t actually in love, but that black-haired-girl-whose-name-I-can’t-remember tries to force a relationship with the Duke, disregarding his feelings.Look, u cant rly go with the "do u truly love the duke" question when u urself are in a "contract" with the duke, and dont truly love him(for now ik ik).. So both are kinda on the same boat here in that department.