Shortly after my divorce at 39 yrs old, I had the good fortune of fucking my ex wife's 25 yr old student teacher. It was flattering to fuck a younger gal, plus I couldn't help but feel a little satisfaction knowing she was my wife's student teacher. Of course, my wife didn't know, but it still felt great.
After a couple of months, I had my eye on a couple of gals that were closer to my age, and I started seeing the younger gal less often. Every now and then she would send me a hot e-mail, and I would end up hooking up with her. In addition to student teaching, she was also taking photography classes, and owning a small photography business on the side, she often sought my advice on things. One day she send me a hot e-mail saying that she wanted me to come over and we could both do some artistic black and white nudes. She actually still lived at home with her mother. Hell, her mother was only about 5 or 6 years older than me, and living in a small town, I knew her mother well. Her mother didn't know about the two of us.
On this particular evening, her mother (a widow) had just left to meet some of her friends to go out dancing. It was storming that night, but she said we safely had until at least 2 am to play. We go to what most people call a small mother-in-law house directly behind her home that she had converted to a studio. In no time at all, we were both naked. She had her camera set up on a tripod, and three studio lights set up. She knew I had an interest in BDSM, and while BDSM wasn't really her thing, she did want to take some BDSM style pictures. We both agreed, no face photos, so she tied me up, hands behind my back, with rope wrapping around my torso. Before she took the first photo, and once she had me tied up, she sucked my dick long enough to get me standing straight up, then took her position behind the camera.
Just as she was focusing in on things, in walks the Mom. Apparently the rain was so bad that the streets were flooding and they cancelled their plans. So here I am, butt naked, hard dick, sitting on an oak table all tied up, with her naked daughter standing behind a camera. Her Mother was so flustered when she walked in, she actually dropped her keys. On an amusing note, she stood there for maybe just a second or two while picking up her keys and said something to the effect of, "Oh I'm sorry, you two kids have fun," and she promptly left the room.
I'm sure some of you have better "Oooops moments, but I will never forget that one.