Hey, it's not a big issue, I guess. If you're still loving her and following the path of winning her stubborn heart, and not going to screw it up in the future, I'm sure the danger's passed
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I don't think that further attention will be focused on this somehow. Well, maybe there will be a couple of dialogues on this issue between the characters. The story shouldn't stand still, we got a lot to look forward to.
In order not to confuse you anymore and finally make it clear for you, let's go step by step according the storyline. Just look.
First of all, you need to develop a relationship with Sara as much as possible. And it doesn't matter what you choose later for Sara's story, love route or friends route, this doesn't affect Ashley's story. The main thing is not to screw up anywhere before. Always be ready to help Sara with Ashley's problem (it's so obvious though). It also doesn't matter if you either tell the truth or want to trick Ashley during your last talk. She won't going anywhere from you (of course, if you're here for her). But of course, the perfect variant is to trick her, you get it (as for me, I have different scenarios). It allows you to get max RPs with both Ashley and Sara. Then you get a scene in your room and another serious talk with her. It's from the guide:
If you have POINT #6 (Ashley path):
If you “Tell her everything” in the “Ashley last talk” and you had a jog with Sara = 1st variant of the Ashley event
If you “Trick her” in the “Ashley last talk” = 2nd variant of the Ashley event
And if it all goes the way you wanted, then you finally find yourself participating the very major event in Ashley's story:
Ashley want to know about sex stuff.
1) Accept = the MC will become a sex mentor for her
2) Decline = The MC will not become a sex mentor for her, but
Ashley will not return to the sorority
As you can see, the Dev assures us that we managed to achieve what we wanted and saved Ashley from the mistake she was going to make. Good job, we did it
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