I notice a tendency from the more eloquent members of the thread to go to great lenghts in justifying Lauras's behaviours (and calling her cheating a sacrifice or a quest for betterment is just that - justifying). Now, I'm not the greatest connaiseur of NTR history and sub-species and whatever, but I see NTR as being plain ole' fetishizing cheating; cheating is, at it's basic level, emotional abuse (the breaking of trust, the breach of boundaries, the taking consent away etc. Just read some real-life stories about cheating and the consequences it has to the cheated party and you'll see why it's a nasty form of abuse; there are always explanations for this form of abuse but never justification). Okay, this is just a visual novel or an almost-game so "no animals were harmed in filming..." but justifying cheating from an abstract medium is just that - justifying abuse but in an abstract form. Why not just call her as it is based on her behaviours: a person without sense of boundaries, flirting with sociopathy (she "saves" Harry by knowingly exposing him to direct abuse) and perhaps a tad of narcissism (the always trying to be in control of the narrative bit), so a toxic person. Her actions being "out of character" is irrelevant - those actions are what defines her character.
And that leads to my point: the only (proper) good ending (one in which a modicum of dignity is restored to the parties involved) would be for Laura to come clean to Harry, get the (much-needed) therapy and break contact with Luca; for Harry to cut all contact with Laura and hopefully to manage to heal in a way that doesn't make him less of an idealist; for Luca to get a form of criminal charge (the attempted blackmail and the roofie-ing being the most obvious).
Cheers