Very nicely done.  The descriptive writing painted a vividly erotic picture.  The abrupt ending...actually was a nice touch...allowing the readers to finish the story in their own minds.  The one improvement I might suggest...instead of starting the story with an explosion in science class lab...perhaps the story could have started as it ended...in mid scene...the explosion, ray gun, new invention, molecular transformation device....I personally could do without the "set-ups" most writers seem to deem important to the story...fact is gts is a fantasy that must remain a fantasy...it doesn't matter how the guy "got shrunk"...any "explanation" will never make the stories "real" .  XtMS didn't write a story that a reader had to wade through, (often times halfway through the story)to find what he/she was looking for.  Great job XtMS...I've added you to my favorite author list, and hope you continue with your efforts.