It was very cold in Ohio where we live, and my wife and I needed to get away for a while. Chuck and Jessica, another couple who have been friends of ours for years, felt the same way. We hit upon the idea of renting a place to stay for a week in in Texas, in a little town on the gulf coast. The place we found was an AirBnB condo. It was right on the beach and had two big bedrooms, each with its own bath, and a nice balcony and deck. I was hoping for a re-occurrence of what I called "vacation sex", where my wife would get a little more adventurous and a little more horny than our usual cycle of fucking every couple of weeks.
Jessica is about my age, a year or maybe two younger. She and my wife have known each other since high school. I've always liked her, and she's fairly attractive. Not usually my type, to be honest, but nice looking and I like her personality. I had gathered from the occasional comment from Chuck, her husband, that they very rarely had sex any more. I didn't have any detail, but I knew he'd been complaining about that for a long time.
This trip was the first time we'd been around them for longer than a few hours during a party, dinner, or day trip. For the first couple of days in the condo, things were perfectly normal. The weather was great, even though it was winter in Texas - still a lot warmer than home. I did notice that Jessica and I were getting along very well. In fact, we two seemed to have a lot in common. Both our spouses spent a lot of time out on the deck smoking or playing games on their phones, leaving the two of us to talk. I was feeling more and more attracted to her for some reason. This, combined with the fact that sex was pretty much not happening, led to some impure thoughts about her creeping into my head. It didn't help matters that she was usually dressed very casually in a tank top and no bra, sometimes with shorts or leggings that showed off her legs and ass quite nicely.
About the fourth day something happened. I was up very early and was downstairs in the kitchen making coffee. Jessica came down to join me, and I poured her a cup as well. We were both moving around the kitchen getting various things out for breakfast. Both of us were still wearing what we'd slept in, meaning pretty loose pajama type bottoms and a T-shirt in my case, and a tank top in hers. As we moved around the kitchen I was trying to keep far enough away, or behind the island counter, so she wouldn't notice that I was about half hard. I tried to keep it out of sight as much as possible. I was doing pretty well until by chance she happened to move past me and brushed her ass right up against my cock. I was about to panic. There was no way she didn't notice THAT. In a split second I could hear her yell, see my wife and her husband run down to see what the problem was, see her pointing out my erection, the disgust on their faces, the yelling, the anger, and the quick and acrimonious end to our otherwise very nice vacation.
Then she did it again... but this time a little more deliberately. She was still facing away from me, and slowly pressed back and ground her ass against my rapidly stiffening cock. I didn't say a word. Once the shock wore off a little, I slowly slid my hands up along her hips, then up past her waist, and around the front of her top, finally cupping her small breasts. As she leaned back a little I found and caressed her nipples, which rewarded me with a barely perceptible low moan as she slowly gyrated her ass against my cock which had now achieved its fully erect state and was throbbing against her.