This was when we were in our mid-20s before we were married, and everything sexual was an adventure and we would do anything. Heard about a dogging site about 20 miles away, so went one Friday night after an evening at the pub where we a few to drink. Met a young bloke around 19 in the pub who hung out with us and danced a lot with her. As the evening wore on, they kissed a few times and he rubbed her bum. She kissed him back and let him feel her breasts, and seemed taken with him. When he went to the loo near the end I asked if she fancied him. She smiled a big 'yes', so asked if she wanted to have him while I watched. Another bigger smiling 'yes' so, when he came back, we got up to go and I told him we were going to a dogging site and if he followed us he might get lucky. Got there and parked way off by ourselves with him next to us. She gets in back and he joins her there. Told him to keep his hands off and just watch the show until I tell him it's his time. I watch from the front seat as she takes off her shoes, pulls off her panties, unbuttons her blouse under her low scoop neck jumper, and sits in the corner facing him in the other corner. Sitting upright, she pulls her feet onto the seat and spreads wide open. Puts her right hand on her pussy and starts rubbing up and down her slit to get herself wet, then puts two fingers in and finger fucks herself, in and out, in and out at a steady pace. She soon pulls the neck of her jumper down to expose her breasts and their nipples, and caresses her tits and rubs her nipples between the fingertips of her left hand as her other hand works inside her pussy. Nipples soon hard as pebbles and sticking out an inch. At about the three minute mark, she inserts a third finger to join the other two inside her pussy inside and ups the speed of her hand. She's really wet inside and you can plainly hear the squelching sound of her wetness as her hand works inside her. She's now also vigorously pinching her nipples with her head rolled back, eyes closed, and the sound of her moaning and hard breathing coming from her open mouth. At about the five minute mark, she starts coming with violent jerks of her hand with her fingers deep inside and pinching her nipples really hard. She's panting and gasping with passion oblivious to the two of us watching, then lets out a series of wails and cries as her hand becomes a blur. Her come lasts maybe 30, 40 seconds until her hand stops and her upper body slumps back, totally spent. I've seen this before and I'm horny with my cock straining inside my clothing. I look at him and he's got his cock out, fully erect, and is wanking slowly so as not to waste his cum outside her pussy. I then tell him she's all his. He leans over and stretches her lengthwise along the seat on her back, and gets her knees up and legs apart. She's still limp like a rag doll from the aftermath of her climax, so he has to position her like I said, and then gets between her legs. He pulls his clothes down to his knees and mounts her, shoving his nice sized cock up her sopping wet pussy, then starts to fuck her. I tell him she'll be groggy like that for another couple of minutes, but she'll enjoy it and then, when she fully recovers, she'll fuck him like a wildcat. Sure enough, as he fucks her for a couple of minutes, she starts responding and soon is fucking him like there's no tomorrow. She's moaning and breathing hard and he's making male noises of a building come. It was so erotic watching my woman with another man! It was our first time and I knew we had to do this again! Another minute or two and he's grunting and then he comes. She comes right after, gasping and panting and making lots of other noises as her body jerks almost off the car seat and bounces against his. Their mutual comes are vigorous enough, the car is bouncing around a bit. When finished, he stays in her, slowly moving his bum, stroking her pussy slowly as they hug and kiss. A few minutes later, when he's ready for another come, she takes charge and fucks him hard with her arms and legs wrapped around him. They go at it for a while until he's pounding his cock into her. She comes, crying and wailing, then comes and shoots another load of cum up her. They lay there for a minute or two until I tell him the show's over. He goes back to his car and leaves as I climb in back. She's lying back with her legs wide apart, cum dripping out of her wide open pussy onto the upholstery of the car seat below her pussy. She looks at me with a shit eating grin on her face and asks if I enjoyed the show. My lustful grin tells I have and she says that was wild and she wants to do it again with another bloke (and that was our introduction into our lifelong membership in the 'lifestyle'. By this time I'm kneeling between her legs with my clothes down to my knees. She reaches for my cock to make sure it's rock hard and says she wants another fuck. I'm really horny from watching and quickly mount her, thoroughly enjoying the feel of his hot cum around my cock as I fuck her for about 20 minutes with me coming the first time within just a few minutes. I keep fucking her and at the end I come again and so does she. We lay there with me on top and my cock 'soaking' in her flooded pussy until it gets soft and falls out. The car seat's a mess with splotches of cum, but they just add to the many other cum stains she and I have put there during our time together up til now. Over the ensuing years, we get married; have the kids, all the while having a very active and interesting sex life, sharing her with other men when we need some variety or extra excitement to keep things interesting.