1) I was about 38 and dating a 19 yo massage therapist who was very sexual. One day while eating her out on my massage table she asked me to drool in her mouth. She just wanted me to let my spit drip from my mouth into hers. I did and it lead to a very intense make-out session.
2) My favorite. A new provider here in Atlanta, although not new to the swinger scene, and I were having our very first session. She was very submissive. I was in between her thighs when she whispered something. I had to ask her 3 times to repeat it and she said " Fist ME!" This lead to one if not the most memorable sexual experience I have had to date. I know some might find it gross or disgusting but I must say that in the moment I have never felt more sexual.