Monica

You come back to your office after lunch and notice there is a light on. You approach the door and listen. You are fairly certain that you can hear the sound of a humming buzz coming from inside.

Opening the door you are greeted by a spectacular erotic sight. Monica sits astride a machine that she's placed on one of the lab tables. She is wearing a pair of fringed suede chaps with a matching vest that is straining to contain her massive breasts. She has no pants, shirt, bra or panties on as she's currently riding a Sybian Machine as if it were a mechanical bull. She has tied a bandana over her mouth to keep from screaming as it seems she reached her first of many orgasms a long time ago.

You lock the door and move over to rescue her from her steed. Removing the gag she gasps, "I thank-ee for yer kindness... I was... mmmmm... hoping to change mounts before that one gave out."

"You're sure, that you can handle a new bronco?"

"Just shut up and get on the table!" She demands.

You comply and find yourself laying on your back as Monica climbs above you with severely shaking limbs. You got a look at the sybian which seemed to be stimulating her pussy and clit quite well and remark that you are a good deal larger than the dildo she'd been inserting.

Her pussy is lubricated from her running orgasms but as you suspected, her body is unready for your size. She shudders and spasms violently as she tries to slide herself down onto you. After a few moments she relaxes and slides fully down onto your cock. She begins to gyrate but you stop her.

With a massive thrust you begin to buck up and down, humping her and using her over-stimulated pussy aggressively. She holds to your waist as she cries out loudly, instantly losing control to a massive wave of orgasmic pleasure. Your jerking and thrusting is so powerful that the button holding the vest closed pops and releases her bouncing melons. She manages to ride you as best she can for ten minutes before she cries out, "Just cum already! I can't take much more."

You relent, and with one final thrust fill her pussy with cum. She falls off of you and lays on the table for thirty minutes panting. The cum dripping from her sore lips. When she finally tries to rise she finds she can't walk and you allow her to rest through the rest of the day in your back room.