It's set, essentially, post-ICk, but actually the first porny bit happens when they're just having a friendly wrestling match which Artemis decides to turn into sex (they're amazons, it happens), so, yes to the first question.
Honestly the only person I can imagine anyone calling "Wondy" in the heat of the moment is Simon Williams. I mean, unless Cassie slept with Slobo or something. (Which she wouldn't, not just because eew, but also because Anita would cut her.)