I went back and looked at that interchange. In brief:
Her: "You make it hard to fantasize about you sometimes."
Him: "Fantasizing about your boss? Do you want your bonus?"
Her: "I'd give up my salary if you slept with me."
Him: "Hahaha. Flirting at work, how shameless."

...doesn't sound like she's expressing real feelings, or that he's picking up on them, and he doesn't seem to be either encouraging her or outright telling her he's not interested.