Not sure how kinky it is, but probably my most memorable, which I have tried to replicate since:
I was 24 and had been laid before but never had a steady gf and easy access to sex. I started seeing a 39 year old woman who was obviously much more experienced than me and taught me a lot.
One night, we were in my basement apartment, and I was titty fucking her. She had a nice rack and was holding them together for me.
At some point she could tell I was getting close, so she stopped me for a second and told me my options of where to finish:
Mouth, face, or tits. I had never come in a woman's mouth before so I chose that option.
I swear to God to this day I have never been as lost in the moment as I was during that orgasm. I literally had to come to (I came then I came to) and remember where I was.
She actually had to shush me because I had forgotten that we were in a shared house and I was making too much noise!
It was intense!