Done the usual.
Done some not usual.
Swapping (MF/MF), sex on a beach (damn sand gets everywhere...), skinny dipping.
Sex in public on a park bench at QE Park in Vancouver with a girlfriend when we were 19/20, received an applause when we were done. Didn't realize we had an audience, it was night time.
Road head for those long drives. Rim jobs.
Sex in front of another couple while they also had sex in front of us.
Group showers.
Drove home to the suburbs after closing a bar downtown with the SO stripped completely naked and in the front seat.
Made home movies, but she destroyed the tapes lest someone else should see it.
Received a blow job until I came in her mouth, but she didn't stop. Continued blowing me over and over again until I exploded a second time, and still did not stop, continued going until I begged for mercy. I was so tender and sore by this point. Couldn't walk.
When we were much younger, had a night out with a group of friends. 6 girls, 3 guys. Grabbed a hotel room at the end of the night because we had too much to drink to drive home. Except I didn't drink too much. 3 of the girls jumped into my bed in their nighties. Bad case of the 'roamin' fingers'. In that case, no sex took place, we were 'just friends' and had to face each other the next day, but it was quite a touchy feely night all around.
What I really really want is for 2 women to perform oral on me at the same time. One licking and kissing the shaft, the other kissing and licking the clean shaven balls. Right to completion.
That's pretty much the only thing I've really wanted to experience that's still outstanding.