looking for a certain story

I really hate to make this my first post, but this has been driving me crazy.

I read a story a while back about a high school (?) age guy who transforms into a futa over the course of a few weeks or months, describing all the changes that occur. His mom and girlfriend help him hide it, buying him bras and what not. By the end of the story, s/he becomes something of a slut at the school, and I think seduces a male teacher into giving him/her a bj.

Vague, I know. The only other thing I can remember is that I think he changes his name from Dennis to Denise, or Stephen to Stephanie, or something like that.

Again, sorry to sponge off the community, but I'd appreciate whatever help you can give!