I don't think he has to worry about whether to drop her or not, as she's already dropped him, it appears. She's just trying to avoid telling him that, hoping he'll take the hints (and they appear to be pretty blatant hints to me).
When speaking of various forms of non-monogamy...it ain't poly if you're just fucking around.
While polyamory, open relationships, and swinging are all distinctly different approaches to non-monogamy, they are not mutually exlusive. Folks can, and some do, engage in more than one of them at a time--and it's all good.