Slightly perverted story idea.

So there's this idea that's been marinating in my subconscious for a few years now. At one point, it seemed like an extremely stupid idea, but the more I really think about it, it heavily reflects on me as a person. It all stems back to that day in my college algebra class when I caught myself staring a bit too much at my "chubby" math teacher.

For some reason I began subconsciously sexualizing her and it just went on and on in my mind, despite the internal struggle of resistance. I finally accepted that I'm on many levels attracted to chubby women. It still sounds weird admitting that, despite the evolution its had in my writing. Basically, the idea stems from a certain person I know who falls in the chubby category. Back when I was in much better shape than I am now, she used to compliment me all the time about my muscles. *cries* I had this weird idea that in order to get chubby girls, I had to be in amazing shape. Actually, it was to get her I had to be in amazing shape because it would impress her. I long realized that was far from the truth, and thankfully she wasn't that vain.

Despite learning she wasn't hung up on physique,that idea still stuck with me. Even when I made that decision years ago to finally join an gym and take back my health, I still felt that once I got back into shape, I could get a girl like her. Society would paint a much different picture about the physical preferences of chubby girls, but I was fixated on being the perfect guy for her, as superficial and flawed as my reasoning was.

This kept on for years as I've gone to the gym, still with that idea in the back of my mind, and it sort of manifested into a storyline. Actually, the most relatable scenario would be from American Beauty, where the father, Lester, wanted to have sex with his daughter's slutty friend. He overheard her saying she'd sleep with him if he we worked out. So he did just that in order to  woo her. Would that same ideology work on a chubby girl. Could a guy be so fixated on having sex with her that he'll literally transform himself into an athlete to catch her eye?

That's the idea that's been in my head for years, and it wants to come out. Truth, it's mostly based on real life, but as a story, it can actually be interesting and I have actual source material to base it on. However, is wanting to have sex with a chubby, or fat girl, enough to drive a full on story, or is this novella material?

I really want to write this, but I have such a huge backlog of projects, and Nanowrimo is too far away. If I did this for Nano, then it would definitely turn into a story regardless of the source material. But there's a far greater question, would this actually be a boy/girl story? If it's based on real life, I can't see the protagonist morphing into a girl, that would almost seem sexist. It sounds more logical for the main character to be a guy, and I'm surely lacking in "normal" stories anyway. We'll see, we'll see.