The absolute hottest thing I experienced was a Sex Truth or Dare game with five friends in my early twenties. We were also drinking (not drunk though) so it helped to loosen every one one and make us all relaxed. I really think that we used that as an excuse as we were already pretty raunchy and dirty to begin with.
One girl masturbated in front of us and I ended up blowing my boy friend in front of the group. My boyfriend also was dared to suck off another of the guys which was hot beyond words to watch.