But back to the topic: do you allow NPC's to follow the "maiden path"?
The answer is probably no...
Of course the NPC girls in these games are generally not really resisting or against the idea of fucking their brother / boss / co-worker, they just need to be convinced a little bit.
Depends on context: if most of the game is non-con/questionable chances are I'm only there for a few fetish scenes and will mentally block out everything else. However if roleplaying as a somewhat decent human being is feasible I usually don't rape random people for some side action. My personal views on consent do not align with modern radical feminism though and the character depth necessary to determine whether e.g. fondling someone at a bar was acceptable
if the scene had happened IRL simply is not there even for many female PCs with internal monologue ("some cute boys are looking my way" [smile at them] "eek, he's rubbing my butt!" [3 clicks later] "ooh, kiss me!" - aside from a case for mental retardation in this "18"-year-old, is this consensual or not?)
One really odd case was Slave Maker (v3?): the entire concept of slavery, sexual or otherwise, is more abhorrent than a substantial fraction of the sexual acts you can engage in with your slaves. Materialistically speaking living as an enslaved house-servant under a filthy rich PC who does
not beat you is vastly superior to what the game shows of life as a free commoner in that world, and the way the game presents it slaves genuinely fall in love with you if you treat them well. (does Stockholm Syndrome regularly cause victims to make unsolicited confessions of love?) Basically the ancient "benign dictator" problem without the hopes and ambiguities of real human societies.