Fantasy come true

My wife and I had often talked of letting me watch her with another man, usually on nights when we had been drinking, a lot. One week she went with me on business trip, she and I and one of my coworkers ended up at a bar. We drank a lot. They were holding hands and sitting next to each other and I thought that it might be the night. The bar closed, we took a taxi back to the hotel, she invited him to our room, but he declined, Dang! One night we even went looking for a man, about 2:00 in the morning after we left the bar, but no luck.
We are in our late thirties, been married almost 20 years but both of us are in good shape. My wife began watching what she ate and started going to arobics regularly to get ready for her 20 year class reunion. So she looked great. About 5'6", 125 lbs, blonde hair, blue eyes and looks smokin in a thong. One weekend, the kids were gone to friends houses for the night so it was just the two of us. We were drinking and watching movies. We live next door to a rent house with college kids and that night they were having a party. We were quite the partiers when we were in college and got to wondering if we could still keep up. So we decided to go next door. They invited us in and thought it was pretty cool that a couple of old people wanted to party with them. We begain talking and drinking and I noticed my wife looking at some of the frat boys and them looking at her. She was wearing a white tank top, already taken her bra off for the night since we were just watching movies at home and denim shorts. Her nipples began to get hard when she noticed them returning the glances. Innocent looking touches and bumps began to occur with one young stud in particular. She went to the fridge to get a beer and he walked by behind her, put his hands on her hips and squeezed by rubbing his semi hard cock on her ass, she pressed back just for a second. I could tell they both liked it. As the party began to fade we decided we still had beer at our place, so we invited to frat boy next door. He quickly accepted.
Once at home she got him a beer and the two of them sat down on the couch, me in the recliner and began watching TV and talking. I could tell the two of them only had one thing on their minds, I had the same thing on mine. Their hands begain to rome and finally they began to kiss, tounges going wild, his hands all over her, she undid his pants and began to stroke his hard dick. Soon them were both naked. She climbed on top of him on the couch and slid down on his cock very slowly. He was going nuts wanting her to go fast, but she loves it slow. His hands were all over her tits. Soon she had his entire dick inside her. She does this thing with her hips where she barely moves but it feels incredible, she started doing it to him. He exploded inside her and she soon followed. I was nearly naked too, from watching. She got up, grabbed my hand and took me upstairs and we had the best sex that we have had in years. I guess Mr. Frat boy showed himself out. Wow! What a night.