Camilla you just need to activate the initial scene for the criminal harem with her not having the necessary stats. When you talk to her in the next event tell her the truth about knowing lexi and she'll leave with not having said stats.It doesn't work with harmony and shiori, they don't leave, they just lower their love; how should I do it?
And besides, how do I remove Camila? Due to the execution event, it appears
With Harmony it probably is best to stop her at purity 65 when you can have sex with her and keep her lp low. Basically ask her out on dates on the phone and have hot coffee until she get pregnant and then tell her to abort. I'm guessing like Cassidy there is a limit to how high lp can be to get them to leave, probably 70-80 max.
Shiori is probably the same as Harmony in you need to impregnate her before 70 lp, since even though you lose lp doing so, that also should show the flag for them being accepting of abortion not be triggered.