Femme Fatale/Playing With

Basic Trope: A sexy, sultry, but morally ambiguous woman, common in detective novels.

Straight: Bob is solving a case, and one of the suspects is Anna, who is a flirty, sultry beauty, and who may or may not be a Honey Trap, working for the Big Bad. No one knows for sure.
Exaggerated: ALL of the suspects are this.
Downplayed: Anna is a beautiful, but not sexy, woman. Where her loyalties lie is unknown.
Justified: Anna is a Double Agent, or even The Mole. It's best that she keeps herself mysterious, but that doesn't mean she can't use her...erm...talents to get her way.
Inverted: Alice is solving a case, and one of suspects is Tall, Dark and Handsome Benjamin.
Subverted: It turns out that Anna is The Vamp-- literally! The beauty was a disguise. She's not as attractive as she seems...
Double Subverted: ...she's even hotter.
Parodied: Anna thinks she's this, but she's a Gonk.
Zig Zagged: ???
Averted: Anna isn't particularly beautiful or morally ambiguous.
Enforced: "All good detective novels have a mysterious, sexy woman, so let's add one."
Lampshaded:

Claire: Bob, you have a new suspect to question.

(Anna walks in, and saxophone music begins to play)

Bob: Saxophone music is playing in my head. Must be a Femme Fatale.

Invoked: Anna is working for the Big Bad. He hired her specifically because she's hot.
Defied: ???
Discussed:

Claire: Be careful. Remember Benita? She was just as gorgeous as Anna and--

Bob: Don't remind me.

Conversed: "There's always a Femme Fatale character in these detective shows. ...Yep, here's one now."