Would you call the girl, or what she does at the end, "corrupted"?
Totally depend of the girl. If she's a young wild one, it's not necessarily corruption, but if she stand more on the mother side, yes, totally. In games, "corruption" is too often seen as a dive into deep depravity, while it's at first a big change of behavior.
Take a kid for whom his parents say that his friends have a bad influence. From their point of view, they are corrupting him, turning him into a person he isn't. And you don't need to necessarily be a good person at first, the kid can be a bully, then being lead to alcoholism, drugs and robberies by the said friends.
Now, to fall back into a sexual context :
Take a woman, she encountered her husband in high-school, he was her first and only love, her first kiss, and her first, and only, man. They haven't done more that kissing before their wedding, his choice, not hers ; being a virgin, she was afraid by her first time, and being in love, she was afraid to loose him, so she never pressed him.
She's now in the mid thirty, living an average middle class life. She never cheated, why should have she ? Her husband is caring, he love her and she love him, they have two wonderful kids, and a decent life, including what seem to be a decent sex life.
She's not shy, she even swim topless in their pool, well at least when her husband isn't here ; he never raised his voice or have been violent, but she clearly see that he don't really like that, despite the neighbors having almost no chance to see her. She also don't care this much what she's wearing if she have to open the door ; she pass a bathrobe if she's naked, or just have her underwear, but unless she's effectively naked, whatever if it's not perfectly tied.
She's not prude, nor frigid, either. They have a (relatively speaking) intense sex life ; well, they had, it's less frequent nowadays, her husband have responsibility at works, therefore less time and energy. But they still do it globally once a week, and it's still as pleasant as usual for her. They don't do "strange things", but she isn't against doggy style or a cowgirl ride. She even suck his dick time to time, and it happened, more than once, that she had no other choice than to swallow.
In short, she's a perfectly average woman in her thirty who, perhaps with a bit of naivety, think that it's how sexuality goes.
Then, one day a young couple move in, being their left door neighbors. A charming young couple, very polite ; she hope her children will become like them later.
There's only one thing about them, they aren't shy at all, but really not at all, and have sex wherever they are. Once, she invited them, with some other neighbors and friends, for a barbecue, and she heard them having sex in the bathroom upstairs. She didn't cared, after all they are young and in love ; it's their life, and even if she never did this with her husband, she understand them. At least it explain the noise she heard sometimes while being in her backyard.
Time pass, slowly. She continue to hear them time to time, but don't really care ; when it happen she go back inside, giving them some privacy. This until the day she was doing some gardening near to this couple backyard, and she heard a girl orgasm like she never heard a girl orgasm. It was stronger than her, she wanted to know, and after taking a glance through the fence, she see that the man was going done on his wife. She known about this, mostly through the few porn movies she watched by curiosity. But she never thought that it could be this pleasant ; porn actresses fake everything, right ? For her, it was just a way to thanks a girl who sucked your dick, and she never felt the need to be thanked for that.
Now her curiosity is triggered. Apparently there's more about sexuality than she thought, and... well let's be honest, it seem clear that sex can be more than just "pleasant". She start to caught herself doing gardening in her backyard, not because the plants need it, but with the hope to caught them again ; and of course it happened. At first she was just listening, but nowadays she often want to also look ; more than once, after that she even goes to the bathroom, masturbating while taking a shower.
She learned a lot about them, and about sexuality. They do anal sex ; she always have been curious about this, but her husband once said that he don't want it and, like she fear that it hurt, she never talked about this. They do other things, way more exotics. Once she even catch them while the guy was pissing over his wife ! At first she was a little disgusted, but she also realized that the girl seemed to like it. Since then, she wonder if she would like it or not ; but it's obvious that her husband would never agree to do this.
They also aren't exclusive. At first she was shocked when she discovered that this time the girl wasn't the wife ; he seemed to love her so much, why is he cheating ? Then, few days later, she saw the same girl again, but this time the wife was there with them ; she was even between the girl's legs, eating her. Few times there were another man, but apparently it's something she do for the husband to not feel guilty to be the only one who've more than her as partner.
Then, one day it was stronger than her. She love her husband, really and deeply, but there's no doubt that she's missing so many things sexually speaking, and that she never had a real orgasm ; she don't compare herself to the girls she witnessed, she compare the orgasms she had with her husband, to the ones she started to had in the shower after watching her neighbors have sex.
It needed some time, but she's ready and determined now, facing their front door. She'll ring the bell, confess that she was spying, and ask them if they accept to teach her everything she was missing...
So... Isn't this the pitch of a corruption game ? A passive corruption at first, then an active one once she ring the bell.
Yet, the woman isn't prude, shy, and not even really innocent. And she also don't need to turn into a slut. She want to finally have an effective sex life, not necessarily to catch-up with the lost time. It's probable that this couple will be the only persons with who she'll cheat on her husband. She still need to have some feelings to have sex, and she like them, they really are nice and pleasant ; she still hope that her children will be like them later... well, perhaps less wild sexually speaking.
But what is sure is that she'll explore her whole sexuality with them. Perhaps she'll discovering herself being submissive, or perhaps is she dominant ; she have the choice, the man is dom, while the girl is more on the sub side. Perhaps that she'll sometimes be there when the girl invite one of her few male friends ; perhaps just for the girl, perhaps also for the guy. Perhaps she'll do the same when it's a girl that is invited, or perhaps that she's not even bi and, while she don't deny to the girl the pleasure to caress her or eat her out, she never return the favor.
All the doors are opened, without the need for the girl to be more than the average woman, and without the need to effectively dive in deep depravity.
And, from my point of view, we need more corruption games like this.
