That's what Oliver used her as. I means it's disgusting, as with most of his behaviour, but that's all they did with her. They actually had a real opportunity with Sara to explore a complex relationship between two women, with both Nyssa, and more importantly for the show, her relationship with Laurel, but they chose the sex with Oliver root. And of course spiced it up by teasing the relationship with Nyssa.
Just thinking how many episodes will it take this show to pass the Bechdel test? I'm not sure Arrow or The Flash ever have.