Nicole and I took dinner together in a local steakhouse, the activity reflective of a night not unlike most. But I'd worked entirely through the previous day, and this evening thought I would just go home to bed, instead of the lab. To bed, but maybe not directly to sleep.

When I put my arm over her shoulder, steering her away from the direction of campus, my assistant gazed up at me with a querulous expression. I explained to her about the all-nighter, and wanting the comfort of my bed. Leaning in, I whispered that I wanted her to take me that night. She had difficulty keeping still once I'd imparted this to her attentive ear, fidgeting against me as she accompanied me to my apartment.

My assistant and I do not play this game very frequently, we having our accustomed roles, but I think it is fair to say that Nicole does not indulge me in this merely for my benefit.

Once safely indoors, I let some of my professional demeanor drop... I cooed to Nicole in the dark and gave her a small kiss, and asked if she was certain she was up for it herself.

"Yes, Doctor," she breathed, her eyes big, shiny. I kissed her again, lingering.

Leaving Nicole to undress and prepare, I slipped discreetly into the bathroom to give myself an enema. Don't look so repulsed... you should be disgusted if I hadn't. I don't know which fantasy world porn stars live in, where one can instantly transubstantiate the contents of one's rectum into Astroglide the moment anal intercourse is proposed (Narnia, maybe?), but it's an awfully convenient place, isn't it? Here in the real world, we're stuck with basic hygiene. The fan masked any sound which would disclose my activity as I made myself ready.

I emerged from the gloom. "Here I am, Nicole," I said, standing over my assistant, who sat on the bed.

She trembled... her hands cradled the toy we use for times like this. She nodded, and I climbed onto the bed before her, stretching out and situating myself. Hugging a pillow beneath my chin, I lifted my ass, presenting myself to her examination, to her use.

I felt gentle fingers daubed in silicone grease delicately probing past my anxious, resisting muscles, preparing me, and sensed her flush of giddy embarassment at the naughtiness of a rare turning of the tables. Her touch in such an intimate, sensitive spot, at once affectionate and clinical, was powerfully arousing to me, and I was instantly erect.

I heard Nicole's soft gasp when she seated the pilot end of the dildo within herself; she required no additional lubricant, being terribly turned on with anticipation. There followed the minute, slick squeak of my assistant's fingers liberally greasing 'my' end of the toy. Nicole drew a deep breath, then huffed with resolve as she got into character.

The blunt head of the dildo nudged meaningfully against my back door. I swallowed, and shivered, attempting to relax, but as you imagine, it's quite difficult.

Nicole rested her hand on my hip in order to steady herself, her other guiding the rubber cock. It nudged my anus again, then bore down in a slow but decisive incursion. I bit down on my lip, feeling myself spread and spread around the brutal toy, that stretching, near-to-bursting feeling growing until at last the thick head eased past my resistance... I groaned into the pillow. Nicole emitted a muffled sound of excitement.

My breath came faster as Nicole pressed on, insinuating inch after inch of the surrogate cock before her until it was entirely seated, a literally visceral feeling of weight within my abdomen, an uncomfortable, beguiling heaviness sending chills through me. I pawed at the bedcovers. Each spasm of my muscles translated along the shaft, letting my assistant feel everything she did for me.

Nicole began to ride me. The mattress squeaked beneath her knees. She knows I can take it rough, but appreciates that delayed gratification is satisfaction increased, and Nicole's constitution is more suited to the slow tease than to spastic motion. She moved her hips with maddening sloth, stroking in and out from harness to tip, making me take every inch; each time she sank into me, I moaned unreservedly, my voice echoing from the walls when I wasn't biting the pillow, that thick rubber plank grinding over the bulge of my prostate until I felt my cock would burst, too sedately to bring me off until I was delirious with the need for release. The dildo stuck tight in my ass when at last I spontaneously climaxed, whimpering abjectly as I jizzed all over my tits, a hot, marshy spot spreading beneath me. Nicole tamed my resistance with firmer thrusts, and a moment later I heard her squeak, hands trembling on my hips while her orgasm chased mine.

The girl still surprises me at times. Ingenue she may be... she played me like an instrument.

We lay there, coupled and catching our breath. Silence reigned again.

"Thank you, Nicole," I said, breathless. She kissed the nape of my neck.

Then, the withdrawal... denial and relief at once. My legs felt like water, my stomach hollow, as I was evacuted by the enormous toy. Nicole and I shared a kiss as I helped her out of the harness, arms clinging to me, the girl lapsing into her accustomed role. I still had the presence of mind to deal with the unsavory biological remnants-- Nicole is dutiful to a fault, but there are limits to what I will allow her to do for me --the dildo submerged in the bleach bucket under the bed; for myself, a glide with a sanitary wipe which went into the biohazard bin.

Curling up with her, I felt warm and malleable, satisfied. She spooned behind me, uncharacteristically, and I held her hand over my heart.