I had an very interesting experience a few years back. I had a friend visiting for the weekend (He was a Dom) and he brought a friend with him. We sat around talking one night after dinner and telling stories when he talked about some of the things he learned over the years. My wife joked that he thought he was making things up, which made him decide to prove to her that we wasn't.
He had her sit on the floor in an indian position and relax, facing him. She was wearing a thin top and a pair of shorts. Very casual, but nice to look at. He had me sit behind her and be quiet until it was time for me to talk. He told me he would let me know when.
He had her close her eyes and relax, while he knelt in front of her, talking quietly and gently rubbing his hands on her upper legs. He never touched her under her clothes, but a few times you could hear her, moan slightly and gently answer him when he asked her questions. When he felt she was ready, he started to tell her that she would hear her name, followed by a command, and when she heard it, she would orgasm harder then she has ever done in the past.
He asked her if she was ready, and she whimpered yes. He nodded to me and I said her name, followed by the word I chose as the command. She instantly reacted, kicking her legs out and kicking herself backwards as her body shook from the intensity of the orgasm. She actually moved so fast and so hard that she knocked me over because I was sitting on the floor behind her.