In the end, Kate will have sex with both, but Nick is first.
(spoiler)
It will be happen in one point in the story when Kate spy to Nick and Julia in the bed at night, but first need corrupt Kate a lot.
It isn't part of one quest.
In one point Kate, after several attempts, changes her mind and takes the decision.
OK it's good to know that Nick will be first coz i'm quite advanced on that quest (he went have a drink from the fridge at night while Kate was sleeping on the sofa twice already, last time they even spoke).
BUT:
- how do i corrupt Kate more? At this time she has 330 open mindedness, only 3 in lewdness, interest in men 897 and in women 44. I can't see a corruption value..
- as for Max, as far as i understand that happens in Alice's house where Kate must be invited and get a job to clean there. But WHO invites her ? Alice or Lisa ? Which one of these 2 do i have to concentrate on in order to get that invitation? And is there another quest that must be completed before that invitation? I mean what triggers that invitation please ?
- I also don't understand if it makes any sense to keep inviting different girls from the school to have a cafe and pay for it all the time. Does that matter for anything? In one of the quests it is mentioned as a condition that Kate must have slept with Alice. But no hint on how to do that ..
- And does it make any sense to invite guys like Dennis or Mike for instance to the cafe? Will Kate have sex with them or other men also?
FYI : I play v 0.31 and never played this game before.