For second story I have chosen again an experience that by itself has nothing too uncommon, but for me it was interesting, with several firsts.
Some time ago we and they lived very close, same block, and I was sort of a colleague of her. They had kids, we too, about same age. We got friendly with play dates (for kids etc. A bit of novelty for us, initially, was that they were black (well, just so happened that being close friends with black family was new both for my wife and for myself). There was nothing too special about them though - they were very educated, very busy, and if anybody would assign some common measures of success or status in society they were certainly distinctly up above us.
We all were really friendly to each other. It turned out though that both our families had sex issues.
She (my soon to be extramarital lover) did not have enough sex from her husband, and in addition to that he would not do oral or consider anything else out of vanilla. So she accumulated a really crazy drive for sex that could not find an exit. I was in a quite similar situation. Even though my wife was (and is) fine with oral and 69, she is not very active, and at that time she was becoming less and less active.
Somehow Trissa (not real name of course, just for this record) and I exchanged a few careful hints ... and it was a now matter of time before one of us would do first step... (after about one year of knowing each other as neighbors and colleagues).
So one day this happened. Trissa needed something related to work (while having day off), my wife was away, and after one momentary touch and look she was all over me, hands grabbing everywhere, and I responded likewise. We moved to her home because she knew exactly that nobody would be there for at least next half-day and very soon I was under her in 69.