Lena is not as shy and prude as basic Ashley, but it's still corruption. At the moment it's a lighter version than GGGB, but we've only covered half of the game. Stalkfap, cheating, sex with everything that moves, become Axel's slave again or go under a perverted oligarch, as for me, this fits the definition of corruption.
Considering some of your other posts, this view does not surprise me in the least, still it is black and white on several points, when the world is shades of grey. While cheating or going back to an asshole like Axel most definitely is corrupt or self-forgetting, your other points are very much a choice of what you do and not corrupt on their own.
Stalkfap is as corrupt as far as you decide to go and the "corruption grade" hinges very much why and what you do with it. Posting some "risk" bikini pics or artsy nudes on your own decision is about as corrupt as buying a packet of chewing gum!
"Having sex with anything that moves" might not be as squeaky clean as some people will want to, but a single or FwB Lena is not corrupt simply by the number of her sex partners. There is more to it than just this.
"Go under a perverted oligarch" is simply metagaming, since Eva "cast" Seymour as the main antagonist of the game, which he does not have to be. He could simply be a bored rich man dabbling in a new hobby and simping on Lena, as some paths of the game very much insinuate. Even Seymour and Lena hitting off from early on does not make her corrupt just so.