I was caught watching porn, not once but twice.  At the very young age of 12.  Cable TV was still in it's infancy.  There was only one movie channel.  First time, it was late at night and the parents were asleep and I was curious about it.  So I changed the channel and turned it on, then I lowered the volume.  Don't think it was more than 15 min later when I was caught.  Got grounded for a month.  My parents then would lock the cable box at night and take the key.  What they didn't know was that I had opened the cable box and rigged it so the key wasn't necessary.  No sooner did the punishment end and I was caught again.  The punishment handed down was swift.  The joyous memories of my youth. I believe if my parents were asked to describe me back then in one word, it would have been a Hell raiser.  

As far as getting caught having sex, been that route too.  Think the worst of them was when I was with my first serious relationship.  We worked together that's how we meet. She had just separated from her husband and was going through the divorce process.  Her deranged ex had a suspicion that she was seeing someone because my car was parked outside almost every night (we worked a night shift).  He decided to break into her house one evening and if it wasn't for the creaking of the stairs, we wouldn't have known he was there.  But yea he caught me fucking his former.  I was fueled that evening with Jack and my attitude was IDGAF. He ended up leaving after a very tense moment or two.

I caught my band mate in college at my house (which was where the band practiced so he had a key) in the shower with his girlfriend. I heard the shower going when I walked in and then I heard moans in there. I was so clueless back then - I didn't ask if I could join in.

Many years ago, I would frequent an S&M "dungeon" and the dom I saw was into sticking her fingers up my butt; she would lay down some paper towels, put on surgical gloves, and apply a large portion of lube. So she is going to town on my butt one day when the door to room suddenly opens and what I assume was either a secretary or a cleaning lady walks in. She looks down at my butt, says "excuse me, wrong room" and leaves. Could not have been more awkward but the session was still fun.

This goes back to high school. My folks were supposed to be gone all day, so I had a girlfriend over. We were going at it when I heard the front door open. I told her to get in the shower, which had sliding doors with that pebbly finish glass that doesn't permit a clear view, just an outline. As soon as my mother walked in, she said she had to go to the bathroom. So she was sitting on the toilet with my naked girlfriend just four feet away behind the glass, and she didn't see her.

Another time we were in my car in a county park in the wintertime. It was probably 9 or 10 at night, and there wasn't a soul around. We were both completely naked. A car pulled up behind us, and we both threw our coats over ourselves. A cop came to my window, shined his light in, and told me the park was closed. I can't believe that he couldn't tell we were naked under our coats. My guess is he didn't want the hassle of writing a report for such a trivial thing.

Another time we were parked at what had become our favorite spot for making out, the top floor of a parking structure in the downtown area. I had my pants off, and my girlfriend was giving me one of her spectacular blow jobs. I just happened to look up, and the parking attendant was looking in through the windshield. He told us to get the hell out. I'm guessing he was watching for quite some time before reaching that decision.