While the arrangement did not last, my wife and I had a very wild six months with another couple we were friends with. Julie and Birch had moved to our town about a year earlier from down south. She was a very open and outgoing personality with amazing green eyes and a body that had very sexy curves with a slightly larger ass that was shaped nicely. Julie had a tendency to wear low cut shirts or leave an extra button undone which revealed plenty of cleavage and, when she leaned forward, allowed a very nice view of her bra-clad breasts. Needless to say, even though my wife, Theresa, and I have a fantastic sex life, I couldn't help looking at those tits when we were together. And Julie knew it.
Birch, being an avid sports fan hit it off with me right away. He was a regular guy and a lot of fun to hang out with, always ready with a laugh over some thing or another. Our wives got along well and hung out together during the day fairly often. As time went on, we all relaxed around one another and got to know one another's tendencies. I tend to be pretty flirtatious and open about sexual topics and, with Julie being the same way, our group conversations often turned quickly to sexual topics. We discussed things pretty openly and laughed a lot about the secrets we'd open up about, especially when we were drinking. Things became very open when it came to topics of sex and I caught Julie making sly looks at me more than once, which I always returned. I think she was also aware of the same looks going on between our spouses. We all senses the tension increasing and I often found an excuse to accompany Julie to the kitchen to mix drinks for everyone so I could "accidentally" let her notice my erection. She occasionally bumped against me while we maneuvered in the kitchen and would grin as she felt my cock against her ass and elsewhere.
I know Theresa and Birch shared some similar moments, though Theresa was much more reserved with her sexuality outside of our relationship, never being overly comfortable being ogled by other men even though it happened a lot. She is a beautiful woman and has a wonderful petite body with gorgeous curves and nice, full tits for her small frame. At 6' 1", I tower over her and have always enjoyed the size differential during sex with her as I'm able to easily manipulate her into any position we desire. Seeing her tiny pussy and small body impaled on my 8" cock is a delight that, even after 21 years together, still thrills me to no end. She is the perfect wife and the perfect sexual partner. But it was obvious we were both feeling a little excitement about something neither of us ever dreamed would happen with another couple.
As New Year's approached, we planned to have Julie and Birch over to celebrate. Theresa told me she and Julie had been planning a surprise and I'd find out what it was on New Year's Eve. I was excited about what it would be and had a strong suspicion it might involve an advancement of the erotic tension that had been growing with all of us. That night, I built a fire on our back patio. We have a secluded back yard with a hot tub near the fire pit and Theresa and I spent many a night naked in the hot tub enjoying one another. We had planned to spend time with Julie and Birch in the hot tub that night and enjoy drinks to bring in the new year. After they arrived, we hung out awhile and had a few drinks, at some snacks, and talked as we listened to music. Eventually, the girls suggested we head to the hot tub and told Birch and me to go on out and that they'd join us shortly. We both grabbed a fresh beer and headed out to stoke the fire and hop in the hot tub.
A few minutes later, here came our wives wearing bikini bottoms and white t-shirts. I was a little curious about the shirts but figured it was chilly so they may have wanted to just cover up till they got in. Of course, a woman's breasts outlined in a nice white shirt has always been a huge turn on for me so I was not complaining! I was taken by surprise when they both hopped into the hot tub and kept their shirts on. The moment the water hit their shirts, I realized what the surprise was - neither lady was wearing a bikini top! It was the best wet t-shirt event I'd ever seen as two sets of beautiful tits, one I had only been able to fantasize about till then, were on full display for us. I was instantly hard, my cock straightening awkwardly in my trunks, and grabbed Theresa, pulled her to me and gave her a deep kiss as I fondled the beautiful breasts I knew so well. I heard Julie laugh and comment how hot it was to see us embracing like that. We sat back into our seats and all laughed about the look on my face as the surprise was revealed as it turned out Birch had been in on the planning, leaving me the only one who was out of the loop. I was thrilled with the result and couldn't have cared less about the secret at that point!