it becomes unreasonable quite quickly.
Yep, these quirks are all tied in the events' code with unique dialogue. Adding more would require lots of edits.
There are really plenty occasion where you can discourage them. I haven't tested it by denying one throughout the chapter 1, but there is later an extra quirk event where you additionally talk about these behaviors with the girls again. No idea if these are totally turned off from this event on then.
Something else about event support of partnerships/girfriend status:
Partner-checks already start to a minor degree from season 2 (winter) on, but these are mainly for the general activities, like exchanging "friend" with "boy/girlfriend" during studying sessions and few optionals like Rogues's jogging event in S2.
More support of partnership begins with the season 3 (spring) finale. It's the first finale taking this into consideration, like kissing instead of hugging.
That's why it's no bad idea to become close to the girls during Spring, although nothing is really mandatory. Otherwise like in my current session, there will be too many relationship events chained up that have hardly any time to trigger in a row while doing the last main quests in chapter 1. The game basically turns into a story-weak grind in the end.
The stats during Winter should be about 200-500, what is already fine enough for serious dating with some minor "fun" in the end. Maybe no bad idea either to finish the dating quests during Winter, so the follow-up events have enough time to trigger during Spring and Summer. As mentioned before, asking to become a girlfriend after the dating quests can be done right away, so don't wait for the girls to waste time. The poly condition might not be met yet, but as long as you don't go to further dates and flirt in public, all should be fine until every girl doesn't mind the others anymore.
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