I'm glad that we can at least agree on this. With the rest, still no progress, but it's fine. Your criteria for corruption is based on actions and attitude (coercion / manipulation) from a necessary third party. And mommysboi's criteria for some reason seems to include NTR that he views as a necessary part... My criteria is simply the difference from where the character starts and where they end, regardless of the intent to corrupt, the attitude or the actions taken or even a third party involved because I view corruption as a path that leads towards the outcome significantly different from where the character started due to
various circumstances. For example, having a shameful repressed kink and then growing into accepting it simply from watching porn in my eyes constitutes as self-induced corruption. Like Ash being influenced by incest porn to seduce her father.
I've read multiple stories that featured different styles / ways of corruption. One stood out to me (and is my favorite) - where the good, moral protagonist tries to be a good supportive friend or lover, and then they end up triggering a corruption path for other characters perhaps even unwillingly or reluctantly, having the best intentions in mind, ultimately corrupting themselves as well in the process because their awareness of normality changes to previously unthinkable status quo. I call it "mutual corruption" because both characters end up influencing each other.
For example, let's imagine this situation (my last attempt to prove that there's more to corruption):
Lena opens up to Ian about being blackmailed by Seymour crying to him that she doesn't know what else to do and that she wants to break away but doesn't know how and considering the poor and unstable situation with her jobs, she can only find comfort that it gives her the opportunity to keep sending money to her parents. In this scenario Seymour is not so much a corruptive force but said unexpected circumstance for Ian and Lena to deal with. And Ian, being the supportive and understanding boyfriend that he wants to be, not seeing the immediate way out and feeling pretty useless, tries to do the only thing he can - comfort Lena and take her worries away to the best of his ability. He tells her that the situation is horrible and he wishes he knew what to do, and they'll try to figure it out as a team but in the moment he wants her to feel safe around him and he lets her know that she doesn't have to fear judgment from him, that no matter what she was coerced into, it wouldn't be her fault even if the animal part of her was deep down enjoying the experience. And if it helped her feel better, she could share what occured on her encounters, which he'd obviously keep secret, firstly to help her follow the non-disclosure agreement while having support system at home, and secondly to salvage her new crazy sexual experience to arouse each other. Fast forward to Lena accepting her situation, with Ian's help learning to let go and enjoy her sessions with Seymour because of how turned on being in a submissive role made her, Ian even telling her to act more seductive around Seymour to feel at least somewhat in control while they're together. And Lena would in time actually be happy with her situation, using easy money to spoil Ian and sort her financial difficulties, helping her parents, even buying fancy equipment to pursue her singing passion. And if Emma-ex-machina found a way to actually get rid of Seymour, she'd feel reluctant to disrupt her newfound happiness, and Ian could tell her that if she wanted to stop, he'd be happy to help to finally rescue her out of her trap, but if she actually loved her new lifestyle and didn't want to let go, then he'd be supportive of that as well, considering how much fun it brought to their relationship.
So, in this hypothetical scenario, who gets to actually corrupt Lena? Is it Seymour with his coercion lucky enough that Ian unknowingly is playing into his hand? Or is it actually Ian, with his misguided attempt to help Lena feel better about her blackmail, causes the change in Lena's mindset? Would you agree that the change in mindset is the key factor for corruption to happen? If not, then I guess let's agree to disagree and stop it at that