This is an experience I recently wrote about on my blog. It is also very relevant to the subject of this thread.
*****
Watching Her Getting Fucked
When my wife and I were first married, she had a job in an office at the college I was attending. Several students on scholarships had part-time jobs in that same office.
My wife became friendly with one of the male student workers who was in his senior year. She invited him over to our apartment for dinner a few times, and the three of us went out to movies together.
He also started inviting her over to his room in the dormatory, and soon they were fucking. That was fine with me. I loved it when friendly attractive guys that she and knew would want so intensely to get inside my beautiful wife's cunt. Sharing her in that way has always been an incredibly powerful turn-on for me.
One night when we had him over for dinner, it got very late, and we were all pretty stoned, so I invited him to sleep over. The three of us laid down on our double bed, still clothed, with my wife in the middle.
We talked and laughed about silly things. But I was starting to get pretty horny.
I started stroking my wife's breasts and kissing the side of her forehead. He joined in, only he was soon French-kissing her.
My wife was clearly getting turned on.
I knew I was not being presumptuous, so I put it to him: "So, man, you want to fuck her?"
He just grinned.
I started unbuttoning my wife's shirt. He joined in immediately. She sat up, and he and I both slipped off her shirt. We each kissed her neck.
"Man, you do the honors," I said, looking at her bra. He eagerly reached around, undid the hooks, and slid it off over her shoulders.
She laid back down, and each of us caressed one of her large firm breasts. We licked the nipples and they got super hard. She was writhing and moaning.
His hand moved down to her crotch, and he wasted no time in unzipping her jeans. Soon his hand was inside her panties, and he obviously was fingering her clit.
"Let's get her naked," I suggested.
He and I got up, and each pulled one of the legs on her jeans. Off they came in a flash. As I threw her jeans on the floor, he grabbed the top of her panties and pulled them off as well.
She writhed, but kept her legs together.
"Now you guys strip down too," she suggested, breathing heavily.
As I undressed, I watched his every move, dying to see his cock for the very first time.
When he was down to just his briefs, they were stretched to the extreme by what was clearly a very substantial piece of meat.
He pulled the waistband out and over his cock, pulled his briefs down, and stepped out of them.
I couldn't help but remark: "Wow, man, what a fantastic cock!"
He seemed a bit embarrassed, but then said sheepishly, "So I've been told."
It was long and very thick and had a perfectly sculpted head. Absolute perfection as far as I was concerned. I could hardly wait to experience the thrill of watching that magnificent cock fucking my wife's hot tight juicy cunt.
But I did not have to wait for long.
"Fuck me," my wife said to him tenderly as she spread her leg wide open.
The head of his cock glistened with precum. He climbed onto the bed between her legs. I laid down on the bed beside them, on my side, with my oozing cock against her leg.
He was on his elbows with his hips gyrating as he rubbed the head of his cock against her clit and inner lips. She reached down and grabbed his shaft. She wasn't much interested in foreplay it seemed, as she pushed his cock head into her cunt.
He got the message, and started to slowly enter her, inch after inch after glorious inch.
She gasped and moaned and muttered "Oh, yes!"
Then he started to thrust -- slow continuous thrusts, each one went balls-deep and then he would pull out far enough that the rim of his cock head was just visible.
I had never seen my wife's passion build quite so rapidly, and in no time at all, she was on the brink. A couple more of those incredible thrusts and she was overpowered by an amazingly powerful cascading orgasm. She was crying out uncontrollably.
Her orgasm went on and on, while he kept up exactly the same rhythm. When her orgasmic delerium eventually subsided, she almost immediately began to build again. His pace began to pick up, and soon it was clear that they were both headed for something really big.
His pace increased even more and then suddenly he stopped at the outward end of this stroke with the rim of his cock head just visible. Then he gasped and pushed all the way in. They both cried out as he exploded deep inside her. She screamed with delight, and they were panting, trying to catch their breath. After cumming and cumming inside her for what seemed to be an incredibly protracted period, he finally collapsed on top of her and they each muttered "Oh, God, oh, God."
They then kissed tenderly, and he rolled off of her.
He looked over at her and said lovingly, "You are amazing."
Then he lifted his head up and looked over at me and said, "Your wife is amazing."
"As are you," I said to him.
There were a few moments of quiet, and then my wife said to me: "Now you fuck me."
I needed no coaxing. I climbed between her legs and shoved my rock-hard cock into her cum-filled cunt. Her cunt was relatively loose given the work-out it had gotten, but that was fine with me. Just three or four thrusts in that hot sloppy cunt, and I too exploded in there. What a powerful cum that was, with our friend right there witnessing it.
I rolled off of her, we each kissed her a few more times, and we all fell off to sleep.