Unable to control herself Katie reached under her skirt and began to masturbate furiously. Try as she might she couldn't satisfy the incredible need building with in her, forcing her on to greater and more frantic efforts. Dropping to her hands and knees her hips began to thrust uncontrollably. Her panties were only getting in the way so she pulled them down and began to rub and knead even harder between her legs. Never before in her life had she been so desperate to orgasm and at a loss at how to reach one faster she began to pinch and pull at her clit. Instantly waves of pleasure shot through her, letting her know that she was on the right track.
She could hear Tiff asking if she was alright, but she couldn't get the words out, every time she opened her mouth to try and talk all she could get out were ragged gasps. Once she took care of her need she would be able to talk, but it seemed like she would never manage to do so.
One good thing was that as she continued it became easier to get her fingers around her clit, which had become the center of her pleasure. The feelings focused there had grown to the point where everything else between her legs was irrelevant. Moaning with growing frustration she wrapped her whole hand around it and began to rub and squeeze rhythmically. This caused her to thrust harder, bringing her ever closer to that which she desired. She was so engrosed in rubbing her hand up and down her clit that she didn't pay much attention to the fact that she could feel something dangling down between her legs until at last she felt a crawling tension followed by sweet relief. Something jetted from her clit with incredible force and the feeling of need vanished.
"I don't know what came over me," she panted.
When Tiff spoke it was in a small voice, "Katie, look between your legs."
Katie did as told and saw that her female anatomy had vanished, replaced by a cock and balls.