With my ex-wife (we met when we were both attending the same university and ending our previous relationships. We dated fairly steadily before we graduated, steadily after we graduated, and got married a couple of years after we graduated):
On the intramural field/golf practice green at the university. The grass was cool, soft and damp in the warm summer night.
A few stairwells in the classroom buildings. In the library (in the bookstacks). We were studying....each other.
In our dorm rooms. Sometimes our roommates were there on the other bed (maybe with their own date, maybe not) and we would be very quiet. The desks in the newer dorms were at just the perfect height for her to sit on the edge while I thrusted up into her. That was the G-spot discovery position for us and although she never passed out, she came close a number of times as she went into the most erotic continuous quivering orgasm. Her eyes just rolled back in her head and she just rolled with it. That was when I was in the same sort of shape I am now with the endurance/stamina of a marathoner.
In her parents house. In my dad's house. At both of her sister's apartments. Once in a hotel room we were sharing with one of her sisters.
In the woods while we were hiking/exploring. We got horny and she would drop her jeans and panties, step out of one leg of them so she could spread her legs, lean forward with her hands against a tree, arch her back and present her ass to me. Other times we would just get naked and make love on the ground. Leaves were pretty crunchy but pine needles weren't too bad. We would usually do it doggy style until she had to lay down on her stomach (her legs would give out) or she'd be riding on top of me.
Probably others I'll remember later, but three really stand out:
The first one:
When we were in Hawaii, we did a 5-mile hike up a trail that passed by a waterfall. There were a few people on the trail, some hiking nude (men and women) or topless once away from the trailhead. We did not strip down while we were hiking. Although we'd fuck outside, neither one of us were that comfortable (yet) to be naked around other people. As we hiked down this trail we could see the waterfall from about half a mile away and the pool at the base of the waterfall from about a quarter mile. We could see there was a nude couple at the edge of the waterfall pool and it looked like they were packing up to get back on the trail. They were leaving as we approached. We put down our camera bags and stripped out of our clothes. I took a couple of pictures of my nude wife with the waterfall backdrop and then we took a dip in the pool to cool off. After swimming around the pool for a bit, we came back together at standing depth, embraced, and I lifted her in the water to slip my cock inside her. We had the pool and waterfalls to ourselves for about 30 minutes and made love in that pool (and yes, the water can greatly reduce the natural lubrication no matter how hot you are). It was a nice way to cap of a hike at the end of a day that had started with us making love before breakfast.
The second one:
In February of the same year we went to Hawaii, we had a massive snowstorm over one weekend and a trip to New Mexico that my workgroup was taking to teach a course had to be cancelled because the flights were cancelled and the airport was closed. Driving to work was out of the question and even public transit systems were shutdown. After the snowstorm we had 13-15 inches of snow on the ground and it was an incredibly cold and clear day with the sky an intense blue against the bright white of the snow. My wife and I awoke knowing that we were not going to work and that I wasn't going to the airport. Instead, we stayed in bed and made love all morning long. I don't know how many times I came inside her in the morning (probably two or three times), but we finally got up, got showered and fixed brunch. Even though we had spent all morning making love, there was still a "buzz" between us as we walked around the apartment naked. There was something about the way the sunlight bounced off the snow and the way the light shone through the apartment windows. We thought about going downstairs and seeing what our neighbor couple friends (Tom and Jill) were doing for the day. They were about the same age as us and had been married for about the same amount of time. But we also figured that like us, the two of them had spent their morning in bed together.
We decided to go out and hike through the woods to the nearby lake to see the effects of this powdery snow (we usually have fairly wet snow). We got dressed for the relatively cold temperatures with thermal underwear under our outer clothes and put on our down jackets and went tromping through the snow. We were out taking pictures. The stark blueness of the sky against the darkness of the trees and their shadows was a photographer's dream and it almost did not need a polarizer filter to make the light standout. Although the snow was powdery, it was still so deep that you had to work to get through it. As we were returning, we came to a clearing in the woods near the top of the hill overlooking the apartment complex we lived in. We sat down in the snow and the next thing I know, she's pulling off her clothes and laying them down on the snow under her. She was laying there taking taking the snow and rubbing it over her skin, particularly over her nipples and between her legs. I took a few pictures of her in the snow as she rubbed herself. Remember, I said there was still a buzz between us. Even though we had made love all morning, it was the hiking through the woods and my semen still dripping out of her that had her wet and hot.
Well, it didn't take me long to get out of my clothes and get into her. There wasn't a lot of foreplay. She wrapped her legs around me and was grabbing my ass to pull me into her. She came the moment I entered her (and again, and again). The warmth of the sun on my back, the cold air against my back as well as the warmth of her skin under me against my chest and abdomen was a really interesting contrast. I was mindful that we were out in the open and that the someone could walk up on us in the heat of our lovemaking. I think she was lost in the heat of the moment. It wasn't a prolonged fucking session and after I came inside her, she watched the steam come of my body. It was the first time she had even see me steam like that. It didn't take me long to start getting cold and so once I went soft and fell out of her pussy, we got dressed and walked back to our apartment. While laying on and arching her back, she pulled her panties and thermal underwear up keeping as much semen in her as she could before she stood up. It was one of the most memorable outdoor fucks we had.
When we got back to our apartment building, we saw Tom and Jill and they asked if we wanted to come to their apartment. We told them that we'd been out hiking and taking pictures and that our clothes were a bit damp from all that activity and we needed to change out of them. We'd come down later. When we got upstairs to our apartment, we stripped out of our damp clothes at the front door. My latest deposit was dripping down her legs. She pranced down the hall to our bedroom. I fixed a couple of cups of hot chocolate for us and took them to the bedroom. We weren't done, yet and she was waiting for me in our bed. Elsewhere, I wrote that eating my own cum was an "acquired taste" and it was precisely this type of situation where that acquired taste was quite handy since I had cum inside her multiple times that day, including in the previous hour. After the outdoor "quickie," we proceeded to make love for the next couple of hours. After cummin in her twice more, we were pretty spent.
We went to Tom and Jill's apartment for dinner and to watch a movie on HBO and maybe SNL, but we could barely keep our eyes open. We finally went back to our apartment where we made love one last time for the day and drifted off to sleep in each other's arms. It was "Our Day in the Snow."
As an aside, although Tom and Jill were potential players in a sexual foursome, it never did get to that point. After my ex and I divorced (and Jill and Tom divorced sometime after that), Jill told me she was certainly willing. By that time, although I had not yest remarried, I was already totally involved with my current wife. And so Jill and I never hooked up.
The third one:
We had sex many times in a public campground (both daytime and nighttime) in a large canvas umbrella tent. One time in particular stands out. One hot and humid July night near the beach, we had the window vents and front door vents open, but we had no lights on inside. I was sitting on a folding cotton canvas camp stool just inside the tent's screen door and we were making love with her straddled across my legs. With no back and no arms on the stool, I could lean all the way back while reaching back and holding myself up with my arms. That allowed her to sit on me with her full weight, to use her legs to stand up and down and have me slide a long way in and out, or she could sit all the way down on me and rock back and forth on me. We had done this and cum this way many times before. And in the heat and humidity of this July night, the sweat was pouring off us.
She had just cum (quietly) in a long set of orgasms while I was leaning back and holding myself up. I loved watching her in that dim light that shone through the tent as she rode wave after wave. She was ready to rest a bit and I pushed my way back up so I was sitting upright on the stool. She wrapped her arms around my shoulders, we kissed deeply for a bit while she "cooled off." Eventually, I gently leaned her back so I could get to her breasts and gently suck one and then the other nipple. I could usually get her to cum again by doing this and going back and forth in sucking her nipples. I could tell she was getting close as I continued to alternate between nipples. A moment later, the next wave of orgasms came and I rocked her back upright so I could hold her while she was cumming. She lifted her feet off the tent floor, wrapped her legs around me, and began to rock/thrust herself against me to get me deeper as she came. I, too, was very close to cumming and we both knew that I expanded to an even larger size as I got close (she told me that when she felt me getting larger inside her she knew that I was within about 60-90 seconds of cumming if I/we didn't slow down to prolong the time to my approaching orgasm. If she wasn't in her own world of riding the waves of orgasm, she would slow down just to prolong the time until I came and take in that extra size or my being super hard).
She was about 30 seconds into this wave of orgasms; legs wrapped around my hips, arms clasped around my back, thrusting and rocking herself so that I was rubbing her very, very deeply. As I was going over my own point of no return and my own contractions were about to start, the full weight of the two of us, along with whatever additional force of her thrusting added, suddenly was more than the fabric of that camp stool could withstand and it tore across the entire width of the fabric almost instantly right at the edge of the fabric where it attached to the stool. Suddenly there was no support under my ass as the stool collapsed under our weight. There was a moment where the two of us were suddenly locked together in free fall, me falling slightly backwards as my legs extended in front of me. That was fortunate because I didn't end up directly hitting the collapsed wooden stool legs with my ass, but I did hit the tent floor (and the ground beneath had a little give because of a sand base). I came to a stop with maybe a little bounce, but she was still trailing behind me in freefall and with her full falling weight, she impaled herself on me at my maximum cumming size.
There was a moment of pain as her full weight pushed me into her as I penetrated her to a depth not previously experienced with a sudden deep stroke. She experienced her own moment of pain, too, which lasted longer than mine. But it didn't stop either of us from cumming. Pain and pleasure. I held her closely as she dealt with both the pain and pleasure and felt me cummimg deeply within her. As her own wave subsided, I asked if she was okay and she nodded and said she was (but the small stream of the tears suggested otherwise). We sat there and didn't move for quite some time. We were almost afraid to move and look. Eventually, I was getting soft enough that I could feel myself beginning to slide out of her. I leaned us over onto our sides, pulled myself out of her, and grabbed the towel that we had set aside for this purpose. She was laying on her side, knees pulled up and asked me to look to see if there was any blood. Without thinking about the fact the screen window and door covers were open, I turned on a flashlight and examined her. I don't know if we gave anyone an interesting view while I was examining her. My cum was dripping out of her, but no blood.
Turns out that the action of sun and age had caused the fabric to weaken where it attached to the stool. We checked the other two stools and they didn't exhibit the same weakening, so it was a matter of chance that we picked the one (in the dark) that would fail. But we could also laugh about it later and say that she lost "a different level of virginity" that night. "To boldly go where no man has gone before!"
My current wife and I have a smaller set of interesting and different sex locations.