That's absolute nonsense. You can tell Robert, you're not interested. You don't go home with Mike. You don't fixate on Jeremy's big dick and you let Ivy deal with him during truth or dare. You burn all Axel's photos and tell him you don't want to see him again. You refuse to model with him at Seymour's shoot. You tell Seymour you're not interested in his deal, however much he threatens you. You tell Marcel you're not obsessed with big dicks. You don't flirt too much with Jack. You don't go along with Ivy's plan to corrupt Holly, and after her party you go home on your own. Lena and Louise just stay friends If you choose to do any of these things, then yes there's a greater likelihood that Lena is going to end up as a slut. But that is your choice, and unless you are a very naive person, it's not that difficult to realise in advance, where making those kinds of choices is going to lead.
Lena is a nude model, so she's always going to attract the kind of guys, who just want to fuck her, and nothing else. And she doesn't have to do anything, because those guys are making all the running to chat her up. Ian on the other hand, does not have women actively pursuing him ( apart from maybe Alison) , he only gets to fuck around by a making a big initial effort to persuade them. So yeah, the player has to try harder to make Lena remain loyal, because she is constantly faced with temptation, that in most cases she never even asked for. Whereas Ian has to go looking for that temptation, because he is not a sex symbol, like Lena is, because of what she does as a model.
It seems to me, you don't like the fact that Lena is the object of so much attention from men other than Ian. But come on, she's a nude model, and that just goes with the territory. It's got nothing to do with her being a slut, or more likely to be one. And everything to do, with her being the centre of attention. Which she can't avoid being, without changing the game and giving her a completely different occupation.
I play this game, with Lena adopting a variety of incarnations from nasty slut right through to totally faithful girlfriend. And there is no difficulty making her into the kind of Lena, I want for that particular playthrough. She literally is, what I choose her to be on that occasion. If I choose for her to be faithful, then that's what she is, and the game doesn't prevent me from achieving that. She may be open to more temptation than Ian is, because the most powerful man in Baluart is obsessed with her, and is deliberately making her life difficult, so she feels she has to take his 'deal'. But in the end, she doesn't have to give in to any temptation, unless you CHOOSE for her to do so.