Standing in the cupboard, strapped to the wall by the neck, my ankles steadfastly secured, was surreal experience.
It was dark, mildly warm, and in a way, it was comforting. How did my Mistress know that seeing her fuck someone else would be such a turn on for me? Actually, I'm not sure that it was - watching her with that guy with the humungous cock was excruciatingly painful for me, since my Mistress was also my wife. I could not help but feel territorial or even possessive about her - I had, after all, devoted myself to her, body and mind first, then in heart and spirit later, which gave her complete ownership of me. I could not bear to think there might be another that could please her in a way I could not.
But the size of the guy's prick was undeniable. My own cock was certainly not small, but it didn't compare to the behemoth she stuffed into her cunt right before my very eyes. I cupped my balls with my left hand and gripped my cock with my right as I watched my wife being carried, impaled, then deposited on her hands and knees on our marital bed. I had a complete side-on view of her taut body as she leaned on her hands and knees, offering herself on all fours to the goon whose cock was already buried deep within her cunt. The muscles in her smooth arms flexed as she braced herself; her breasts swayed gently beneath her, the nipples erect and pointing downwards to the bed. Her back was slightly arched, her butt-cheeks round, her thighs white and welcoming. I wished it were me who was about to fuck my Mistress, not that idiot. I knew being fucked on all fours was the way she liked it best.
His hands tightened around her hips as he slowly withdrew his cock from her slippery wet cunt, then began to slide it in and out at a steady pace. I felt my own cock harden immediately - watching my Mistress be dominated like that was such a turn on. I put my hand up to my mouth, spat in my palm twice, then returned it to my rock hard prick, and began to stroke as I watched my wife take that mammoth cock right up her snatch. I imagined what it would like to be that guy right now, every square inch of her cunt dominated by that great galloping prick, her pelvic floor muscles struggling to contract around it, having been stretched beyond capacity to accommodate its girth.
I dropped my mouth open and began to breathe heavily, but it was not easy with a gag in my mouth. Instead I drew air roughly through my nostrils, being careful to keep my head still so I could see my wife through the crack in the cupboard doors. From that position, the guy fucking her was cut right out of view - I could almost pretend he wasn't even there. I tightened my grip on my cock and began to drag my hand up and down the shaft in time with my wife's swaying.