As you look at the small, dainty right hand and your pretty feet, you slowly realize just how amazing this stream is. Maybe it's the enchantment getting to your mind or something, but even if it is, that doesn't change the fact you're fascinated. So you decide to try something weird- you gently lower your face to the water and try and drink a little of it.
Your whole face gets splashed, but it tastes amazing. A weird mix of salty and fresh water, and somehow you can tell it's pure. As you look at your reflection in the water, you watch as the contours of your face subtly change. Your your eyelashes lengthen, your nose shrinks, your lips puff out, your jawline turns less pointed and more curved. It's definitely you in the water still, but you look a lot more feminine. You touch your cheeks and feel your stubble has vanished, and when you gasp you notice your voice has turned higher-pitched since your larynx has shrunk.
As your brain starts to process all this, confusion is turning to gender euphoria. You start to like this, to want this. Once you've washed your other hand and your arms in the stream, you pull off your top and run your hands, still soaked with stream water, along your torso. For some reason, your hands fixate on your chest and nipples, and as your torso softens and slims inwards into feminine proportions, you feel your chest turn more sensitive. The budding flesh around your nipples steadily rises under your hands and the teats turn erect and pleasurable to touch. As you exhale, you feel your boobs grow larger and softer, and when you look in the water you realize you've changed almost everywhere from the waist up.
You can't resist the urge to finish off these changes, and before you can stop yourself you pull your jeans and underwear off, and step into the stream eagerly. The current seems to slow so much it's barely brushing against you, and you can see through the water to your body clear as crystal. You feel your butt swell and soften and your hips widen, and when you climb out you notice your legs are suddenly soft and smooth. But the thing that captivates you is feeling, and watching in the reflection of the lake, your penis changing. The feeling is indescribable, as you see and feel your balls move up inside you and your shaft slowly recede into your body, the vanishing weight in your crotch feeling oddly freeing. You see a slit and lips form from your emptied scrotum as it opens to form a vagina, and your primal urge to fill things suddenly changes to a need to be filled. Thoughts of handsome men with large hard cocks start to manifest in your head- you're clearly a heterosexual woman instead of a heterosexual man. And the tiny nub that was your penis settles in above your newly-formed pussy, becoming your clitoris.
You look at your reflection, and see a pretty young woman. Somehow, it still feels weird to believe that's you.