(author comment: rescuing this because a sex storyline is in the PG-13 section of the site, where it doesn't belong)
Suddenly the loser feels a strange crawling sensation. His head spins and he almost falls over. You fold your arms, watching him, feeling little pity for his narrowminded wishing and his intention of taking advantage of a woman who wanted to help him (though it feels strange to think of yourself as a woman).
The transformation is swift and remarkable to be able to watch -- his short unkempt greasy hair turns longer, silkier. The body hair on his skin thins and vanishes and tightes backwards. Acne clears up, her clothes shifting in color, shape, nad texture. He wished you would want to have sex with him, and thus he is becoming exactly what you would desire: you were a straight male at one time yourself, after all.
She looks up at you with shocked eyes, and a dazed expression. She has become in body, heart, and mind your ideal woman -- whether she likes it or not. You feel a very slight pang of guilt, given your own transformation at the hand of a poorly made wish, but you know now that like your greed she earned what she got. The wish didn't come out exactly as worded: You don't intend to have sex with her, but you sense that with time you could be persuaded with an individual of this beauty...