She's good enough that Bruce can tell she's good despite never having been kissed before. He's suddenly very aware that there's a very fit woman literally in his face and he has no idea what to do with this information.

She laughs. "Let's get you out of those things, shall we?"

Gulp. He'll just hold very still and let her undress him, unless she seems to want him to help. 

She does not! She strips him and then watches him like a butcher considering a cut of meat. 

He shares many features with a cut of meat, such as motionlessness and having blood, and also has additional features, such as worrying that this evening is going to end with his corpse getting dumped in a river.

She gets between his legs and takes Bruce into her mouth. 

?!?!? !

Somehow in spite of everything else going on this is a pleasant sensation. Bruce gets an erection and also the urge to throw up.

Harriet has quite a lot of practice in sucking dick. She does it dominantly, almost violently; there's a general air that she sure does have the most sensitive part of Bruce's anatomy in her mouth and while she is not at the present moment biting down this could change at any time. 

Bruce is terrified and aroused and alternating between "frozen" and "twitching randomly". He wants to pull away; he wants to thrust into her mouth; he wants the ground to open up and swallow him.

Harriet makes a pleased whimpery noise, pulls off, kisses him again, and takes his hand and puts it on her clit.

dhsfafdjflglsh what do (that's a very unexpected collection of textures) she probably wants him to do something and he needs to figure it out before she gets impatient. He tries moving his fingers kind of randomly.

She sighs, says "incompetent boy," grabs his hand roughly, and moves it in the way she wants.

He flinches again, possibly at being grabbed and possibly at being called incompetent, and does as he's told.

She shudders and whimpers under his fingers.

This is the point where a movie protagonist would take advantage of her distraction to jump out a window or something, but Bruce is entirely too chicken and also doesn't know what the next step after jumping naked out of a window in an unfamiliar neighborhood is, so he just keeps going in the hope that if he makes her happy enough she'll let him leave afterwards. 

Eventually she feels satisfied and reaches between his legs. 

And here he had been doing so well at forgetting he was attached to a human body.

She jerks him off roughly and skillfully until he's hard again, then gets on top and guides him inside her.

"Good boy."

There's probably a context in which this sensation would be amazing instead of terrifying and overwhelming. There's probably a context in which being called a good boy would make him feel happy and proud instead of disgusting. Maybe.

She wraps a hand around his throat. "Did anyone see you leave, I wonder."

Okay yup this is the part where she kills him. He could say someone saw them but she knows he'd want to say that either way. She's not pressing down (yet) but he still can't breathe.

She laughs in delight and begins to move fast.

He might be about to have an orgasm and he might be about to have a heart attack and the only good thing about this situation is that one way or another it physically cannot last forever.

She pins Bruce's wrists to the bed and kisses him and keeps moving.

Bruce convulses like he's being electrocuted and makes a muffled noise between teeth clamped down on his tongue.