Back in college I had a friend who came and visited me one summer for a day. I spent most of the day serving as a "tour guide", but near the end we found ourselves laughing on a beach. I still remember the view of her bent over ass, her pushed-up cardigan and her relaxing/winking hole whenever I pulled out for a quick readjustment.
The funniest part: a little paranoid, at one point, I thought I heard a group of people coming down, so I pulled her back onto my lap to pretend we were just a "couple" making a sand castle. She pulled her jeans up a little in an attempt to hide what was going on. My cock was still fully up her ass at this point. Sure enough, a couple of dog walkers came down, but this was the part that really made me sweat: when they walked by us and one of the dogs started making it's way toward her ass on my lap. Thank god the dog was leashed and the owner had the sense to pull back on it (no doubt he saw the sides of her bare hips on my lap and could at least partially figure out what was going on). We said our "hi"'s and the dog walkers moved on. Close call.
Even if it was crowded, and even though it's too risky in our country
If we're out for a meal or a night out, Peter will often take either chris or katie into one of the restrooms, plant a load up their ass and replug them. (chris and katie are always plugged when we go out.)
The toilets in the Starbucks in our local city have seen a good anal fucking now and again.
Various times when we've been parked in the car, and one great trip where I drove, and Peter sat in the back with chris next to him, and katie was undressed from the waist down, on Peter's lap, with his cock up her ass. I'm sure a few of the cars we passed had people in who worked out what we were doing.
We've done dogging sites a few times. chris and katie bent over the car while Peter and I fuck them, with people watching and jerking off. It's surprising how quickly people gather around once they realise someone's getting fucked anally.
I've fucked chris in one of the adult stores on the motorway near us. We stopped in to have a look when we were coming home after visiting friends, and we ended up buying a new strap-on. I couldn't wait to get home before using it, so asked the guy serving if he'd mind if we used one of the changing rooms to try it out. He smirked as he said 'sure' and I added lube to the pile of things we were buying, and after we'd purchased everything, I patted chris' ass before he and I went into the changing rooms where I fucked chris up the ass until I cummed.
There's always something about fucking in public