I know that you can excerise your PC muscles to get tighter during sex and to orgasm better. I don't know if it actually makes you smaller. I know not having sex or using a vibrator for a while can tighen up your muscles as well, but that's a big sacrifice.
honey, you're 15, why in the world would you need to get any tighter? A mack truck drive on through there? Heady & eleria are right though try kegel exercises, they do work.
Yup, Kegel's are a gal's best friend... and a guy's for that matter, lol... I also heard about ben-wa balls or something, some weighted balls that you insert and your muscles get strengthened because you tense them to hold them in? Not sure..... Yea, I don't think it matters how young you are, some gals are just stretchy or whatever than others, it's muslces, and everyone's musclature (sp?) is different. Good luck and be safe!