It was called "power transfer". Liza had given Nils absolute power over her body long ago. She had transformed herself into his personal painslut. Taking one more stroke from him than she thought she could possibly bear, or maybe five, or maybe even ten strokes absolutely thrilled her. Receiving the pain from Nils fulfilled Liza in some warped way that even she couldn't fathom. Try as she might, she couldn't explain it. She didn't know exactly why or how the pain fulfilled her, but she knew she HAD to have it. She would inevitably have her strongest orgasms after Nils had whipped and tortured her the hardest.
"It is just the way we are wired", she often thought to herself when contemplating her dark relationship with Nils. It was as simple as that. She WANTED and NEEDED to hurt for Nils and to cum for him. All the pain she endured at his hand and all of the resulting orgasms were for him. If she ever perceived that she, herself, had control over any of the pain she was subjected to, then the dynamic of her power relationship with Nils would be lost. It was the forbidden loss of control that made the juices flow for Liza. The mere thought of being tied up helpless and at Nils' mercy pushed her to the brink of orgasm time and time again.
She was a girl who needed her limits pushed and Nils gladly supplied the pain and humiliation that pushed her to the very brink of her limitations. She never felt more alive than when she went under the strap for Nils. She loved the erection it gave him when she absorbed the pain and cried out in anguish. He was her true sadist/lover. Nils was her "fantasy man", the only man who knew her deepest and darkest needs.
As she assumed the punishment position on the bed, her mind would wander as Nils tied her legs and wrists to the four corners of the bed. On her knees and elbows, she would stare down into the soft mattress and began to ponder her relationship with Nils. She had the best of both worlds. A man who loved to whip her and hear her cry out in pain and, at the same time, a man she trusted with her very life. What an enigma their relationship was! She knew instinctively that he loved her and would let no permanent harm come to her. Such a strange, perplexing dichotomy, this secret relationship she shared with Nils!
At the beginning he would whip her bare ass lightly with his evil-looking leather strap. One of his favorite instruments of pain, the strap was made of a soft, tanned leather with several holes sadistically drilled into it so as to heighten the recipient's torment. Later when it was swung with more force, it would leave little round marks on Liza's derriere, giving her ass the look of a pimpled teenager's face.