You don't see a choice of abandoning a friend in need, who you have already promised caring for, to go have fun and eat overpriced ice-cream, as a one related to morality? Jill had made very clear the type of dude she 'd be interested in and it's definitely not the dude who would do that. There is a thing in writing called characterization. Which means an established character needs to act in accordance to said characterization. Not the case here.
Lemme put it this way. If the choice was between seeing her, or going out with your DIK daddy to have steamy 3some with horny strippers (hottest scene in the game btw), the point loss would have made perfect sense. The way it is now, it makes absolutely none.
"Jill had made very clear the type of dude she 'd be interested in ".
in that case you will not be on the sage path at all, and you will not have this dilemma. MC only accept automatically to Help Sage, if you are on her path. if you are not, She ask you, and you can decide if you want to help or not. and if you still agree, but then the Girl who are you interested in dating, and she is intrested in you show up and ask you out for a date, you expect that the girl should understand that you dumping her for a friend.
Its seems its your own dilemma, and not the game fault.
this is a either a decision between 2 love interest, or a love interest and a pal. and a pal would understand that you goes for the pussy.
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but if it's a decision between 2 love interest, Jill has every right to be upset, that you rather spend the time with another girl, regardless of that she is sick or not .