Slut Holly only really comes into being, because Ian ignores her. So you're going to need another opportunity for them to hook up, which so far hasn't happened. I suspect it will though at some point. Obviously, the route I was suggesting, was one where Ian and Holly probably never hook up. But he's still her friend, and is more and more surprised by the dramatic changes to her personality. Which he already is to some extent, on that kind of route. The route I'm envisaging is where Holly continues to want to emulate Ivy, which is why I suggest she may get breast implants, plus tattoos and piercings at some point. But if she does hook up with Ian in the near future, she'll probably stop being so influenced by Ivy, on that route. So we could end with two variations of her slut route. One where she's closer to the normal Holly route, and one where she basically becomes a badass bimbo like Ivy.