Talk about jumping to conclusions.
You can currently push Holly enough to maximize her holly_change variable regardless of her relationship status.
The game is like, half done at this point. And Holly's relationship with Ian has barely started. Pretty early to presume you won't get any opportunities for "good scenes" with Holly in the other half, wouldn't you say?
Yeah you can push Holly to be "corrupted" (better words for this game would probably be "outgoing" or "free-spirited") regardless of her relationship with Ian, she just won't cheat on him no matter what right now because she's very happy to be in a relationship with him.
Having her more "corrupted" will slightly change her sex scenes with Ian (i.e how much she can get into it while trying to give him a blowjob), in all likelyhood this trend will only continue into her being more active and confident during future sex scenes and/or willing to try new things.
Worth noting there's nothing in the game blocking Ian from sleeping around with everyone but Lena while he's in a relationship with Holly. He mostly justifies it to himself as "he's still just getting to know Holly and she knows he's not super ready for a serious relationship just yet" but he also feels some guilt over sleeping around. If that ends up blowing on his face later on maybe a highly "corrupted" Holly will be a bit more "vengeful" than one would expect.
